Answer:
For 5 s the ball will remain in air.
Explanation:
Given:
Displacement of the ball is equal to height of cliff, [tex]S=120\ m[/tex]
Acceleration of the ball is acceleration due to gravity, [tex]a=g=9.8\ m/s^2[/tex]
Assuming the ball is dropped from the top.
Hence, initial velocity of the ball is, [tex]u=0\ m/s[/tex]
Let 't' be the time the ball takes to reach the base of cliff.
Now, we have to use the Newton's equations of motion that relates displacement, initial velocity, acceleration and time.
So, we use the following equation of motion:
[tex]S=ut+\frac{1}{2}at^2[/tex]
Plug in the given values and solve for 't'. This gives,
[tex]120=0+\frac{1}{2}(9.8)t^2\\120=4.9t^2\\\frac{120}{4.9}=t^2\\t^2\approx25\\t=\sqrt{25}=5\ s[/tex]
Therefore, the time till the ball is in air is approximately 5 s.
Which of the following is evidence that supports the particle model of light
Answer:
White light disperses into full spectrum of color when shined through a prism due to refraction.
Explanation:
This experiment was performed by Isaac Newton when he passed a white light through a glass prism.
A sound has 13 crests and 15 troughs in 3 seconds. When the second crest is produced the first is 2cm away from the source? Calculate
a. The wavelength
b. The frequency
c. The wave speed
Answer:
The wavelength will be 4 cm, frequency will be 4.66 Hz and wave speed is 18.6 cm/sec
Explanation:
Given:
No. of crest = 13
No. of trough = 15
Time = 3 seconds
Hence, 1 crest or 1 trough = [tex]\frac{1}{2}\lambda[/tex]
therefore,
13 C + 15 T = [tex]28(\frac{1}{2}\lambda)[/tex]
=[tex]14\lambda[/tex]
Time given 3 seconds
= [tex]\frac{3}{14}s[/tex]
[tex]\nu= \frac{14}{3}[/tex]
[tex]\nu= 4.6 Hz \approx 5 Hz[/tex]
2 cm distance is travelled is time period
[tex]\lambda = 4 cm[/tex]
Again wave will travel in 1 T = 4 cm
wave speed v =[tex]\lambda\times\nu[/tex]
= [tex]4\times\frac{14}{3}[/tex]
= 18.6 cm/s
I NEED HELP BADLY
While driving her car at 40 m/s, Andrea (with a mass of 50-kg) stops short to avoid hitting a squirrel crossing the road. If the seat belt is in contact with Andrea for 0.5 seconds, determine:
a.) Andrea’s initial momentum
b.) Andrea’s final momentum
c.) What is the change in momentum (impulse)?
d.) What is the force that the seatbelt exerts on Andrea?
Answer:
a) Andrea's initial momentum, 200 kg m/s
b) Andrea's final momentum, 0
c) Impulse, = - 200 Ns
d) The force that the seat belt exerts on Andrea, - 400 N
Explanation:
Given data,
The initial velocity of the car is, u = 40 m/s
The mass of Andrea, m = 50 kg
The time period of deceleration, a = 0.5 s
The final velocity of the car, v = 0
a) Andrea's initial momentum,
p = mu
= 50 x 40
= 200 kg m/s
b) Andrea's final momentum
P = mv
= 50 x 0
= 0 kg m/s
c) Impulse
I = mv - mu
= 0 - 200
= - 200 Ns
The negative sign indicated that the momentum is decreased.
d) The force that the seat belt exerts on Andrea
F = (mv - mu)t
= (0 - 200) / 0.5
= - 400 Ns
Hence,the force that the seat belt exerts on Andrea is, - 400 N
The neck and bottom of a bottle are 0.5cm and 0.4cm respectively. If the cork in the neck is pressed with a force of 1kgwt and the bottle is full of oil. What is the force in te bottom due to the load
Answer:
0.64 kgwt
Explanation:
You should check that the diameters of the neck and bottom are correct. That is a very small bottle, and the neck shouldn't be bigger than the bottom.
The pressure on the cork = the pressure on the bottom
P₁ = P₂
F₁ / A₁ = F₂ / A₂
F₁ / (π r₁²) = F₂ / (π r₂²)
F₁ / r₁² = F₂ / r₂²
(1 kgwt) / (0.5 cm)² = F / (0.4 cm)²
F = 0.64 kgwt
Round as needed.
Δ→ Δ→
5N 6N
what is the net force?
Answer:
The net force acting on the body, F = 11 N
Explanation:
Given data,
The force acting on the body, f = 5 N
Another force acting on the body, f' = 6 N
The direction of both forces is in the same direction.
The net force is given by the resultant vector,
[tex]F= \sqrt{f^{2} + f'^{2} + 2 ff' Cos \theta}[/tex]
[tex]F= \sqrt{f^{2} + f'^{2} + 2 ff'[/tex] (∵ θ = 0)
[tex]F=\sqrt{(f + f')^{2} }[/tex]
F = f + f'
= 5 N + 6 N
= 11 N
Hence, the net force acting on the body, F = 11 N
A car has a velocity of 26 m/s and goes down to 8 m/s as it approaches traffic. Was the some sort of acceleration?
Your answer:
Yes
No
Maybe so
Answer:
Yes
Explanation:
This is negative acceleration, also known as deceleration where the speed is reduced from high to low at a specific duration.
You push a loaded shopping cart 5 meters along the ground with a force of
200 N. What work have you done on it?
O A. 9,000 j
O B. 2,500 j
O C. 2003
O
D. 1,000 J
Answer:
D
Explanation:
Work done w = force F × distance d
F = 200N and d = 5m
: w = 200 × 5
w = 1000J
A block of mass m = 75 kg is hanging on a vertical rope of length L = 12 m. What work is done by the
gravitational force when the block swings to a position where the rope makes an angle θ = 40° with
the vertical?
Answer:
2100 J
Explanation:
Draw a picture. Notice that the rope forms a triangle, where the hypotenuse is L and the height is L cos θ. The height of the mass is h. The total height is L, so:
L = h + L cos θ
h = L − L cos θ
The work done by gravity is force times distance:
W = mgh
W = mg (L − L cos θ)
W = (75 kg) (9.8 m/s²) (12 m − 12 m cos 40°)
W = 2063 J
Rounding to two significant figures, the work done is 2100 J.
1. a. What is the name of the 2d Century Roman Scientist and Astrologer who created a set of "Handy
Tables of data to compute the position of the Sun, moon and stars?
Answer:
Ptolemy
Explanation:
Answer:
the name of the 2d Century Roman Scientist and Astrologer who created a set of "Handy Tables of data to compute the position of the Sun, moon and stars" is:
Claudius Ptolemy.Explanation:
Ptolemy lived between the year 100 and the year 170 (2nd century), time in which he contributed different bases to astronomy, geography and even astrology. In the first-mentioned area, his geocentric model can be highlighted, with which he mentioned that the Earth It was the center of the universe and therefore it was motionless in the middle of it, and other stars such as the sun or the moon revolved around it and, although in that reasoning it was wrong, it provided fairly accurate means for the time in which the displacement and retrogradation of the planets can be calculated.
Neutrons released in a fission reaction can strike other nuclei and cause ______.
Question 16 options:
fusion reactions
chain reactions
radioactive decay
an electron avalanche
Chain reactions
Neutrons released in a fission reaction can strike other nuclei and cause chain reactions
Explanation:
In nuclear fission reactions, the heavier atoms split into into lighter atoms, releasing neutrons at high velocity in the process. The neutrons hit other heavier atoms in the vicinity and split them too releasing more neutrons. This continuation is called chain reaction. The more the released neutrons the higher the rate of chain reactions. This causes too much energy to be produced at a go until an enormous explosion occurs (like in bombs).
In controlled nuclear fission such as in nuclear reactors, the number of neutrons is controlled so as to prevent the reactor from exploding. A wall that absorbs excess neutrons is used to control the number of chain reactions to prevent the release of too much energy at once.
Learn More:
For more on chain reactions check out;
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Final answer:
Neutrons released in a fission reaction can cause chain reactions, which are sustained cycles of fission that release significant amounts of energy.
Explanation:
Neutrons released in a fission reaction can strike other nuclei and cause chain reactions. This process begins when a neutron collides with a nucleus, such as uranium-235, causing it to split into two smaller isotopes and release additional neutrons. If these neutrons then collide with other uranium-235 atoms, they can cause further fission, perpetuating the cycle. A sustained nuclear chain reaction can lead to the release of large amounts of energy, which is the principle behind both nuclear power generation and the explosive power of nuclear weapons.
we can see our face clearly on mirror why cant we see our face clear on aluminium or irion plate
I need at least 5 sentence
Because specular reflection occurs with a mirror, while diffuse reflection occurs with aluminium or iron plate
Explanation:
Reflection is a phenomenon typical of waves (such as light wave), that occurs when a wave bounces off the surface of a certain material, going back into the original medium at a certain angle, without changing speed, frequency or wavelength.
The direction of the reflected ray is given by the law of reflection, which states that:
The incoming ray, the reflected ray and the normal to the surface all lie on the same planeThe angle of incidence is equal to the angle of reflectionDepending on the type of surface, two different types of reflection can occur:
Specular reflection: this occurs when the surface is perfectly smooth. In such a case, all the incoming rays of light hit the surface with same angle of incidence, therefore they are reflected at the same angle. This means that a perfect and clear image of the original object can be formed: this is the case of a mirror.Diffuse reflection: when the surface is not smooth, the imperfections on the surface are such that the incoming rays of light hit the surface at different angles of incidence. As a result, the rays are reflected at different angles to each other, and therefore no clear image of the object is produced. This is the case of aluminium or iron plate.Learn more about reflection and other wave phenomena:
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how does earths movement through space impact the human experience
Answer:
In space, astronauts lose fluid volume—including up to 22% of their blood volume. Because it has less blood to pump, the heart will atrophy.Under the effects of the earth's gravity, blood and other body fluids are pulled towards the lower body.
Explanation:
If 10 calories of energy are added to 2 grams of ice at -30° C, calculate the final temperature of the ice. (Notice that the specific heat of ice is different from that of water.) T.F =
-20° C
-30° C
30° C
40° C
Answer:
-20°C
Explanation:
ΔQ = m c Δt
here ΔQ is heat supplied which is 10 calories , m is mass which is 2 g , c is specific heat capacity of ice which is 0.5 cal/(g C°), Δt is change in temperature which here is to be calculated.
re arranging the equation we get
Δt = ΔQ/(mc)
= 10/ ( 2 × 0.5)
= 10/1
= 10 C°
final temperature = -30 +10 = -20°C
hence option is A
you push a book a distance of 5 meters with a force of 10 newtons for 2 seconds how much work did you do on the book
Answer:
50 J
Explanation:
Work, W=Fd where F is the applied force and d is the distance
Substituting 10 N for F and 5 m for d then work done on the book can be expressed as
W=10 N* 5 m=50 Nm= 50 J
Therefore, the work done is equivalent to 50 J
A 1800 kg car is parked at the top of a hill 4.7 m high. What is the gravitational potential energy of the car?
Answer:
Gracitational potential energy of the car is 84600J or 84.6KJ
Explanation:
Given that the formula of G.P.E is mgh. So use this formula to find gravitational potential energy :
G.P.E = mgh
m = 1800kg
g = 10m/s
h = 4.7m
G.P.E = 1800×10×4.7
= 84 600J (joules)
= 84.6KJ (kilo joules)
The greater the speed of speed gas particles in containers, the
Greater the collision
Explanation:
The greater the speed of gas particles in the containers, the greater the collision of gases with the container and between themselves.
The speed of gas molecules increases when their kinetic energy increases. This causes a surge in collision between the particles and the wall of the container. A gas is composed of large number of molecules moving at different speeds. When the temperature of gases are increased, they gain more kinetic energy and their speed will increase. This leads to an increase in effective collision between gas particles.Learn more:
Kinetic theory https://brainly.com/question/12362857
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What organism would be at the top of the energy pyramid
A) algae
B) barracuda
C) reef shark
D) snapper fish
how to do this question
Answer:
64°
Explanation:
The triangle is an isosceles triangles (both legs are equal to the radius of the circle), so that means the base angles are the same.
Angles of a triangle add up to 180°, so:
128 + 2x = 180
2x = 52
x = 26
∠1 is complementary to the base angle, so:
∠1 = 90 − 26
∠1 = 64
An electric heater of 1000w is used for 2 hours a day. What is the cost for using in for a month of 28 days, if 1 unit costs 3.00 rupees.
Explanation:
total consumption in a month - 1000×2×28= 56000 w-hrs
1 unit = 1Kwh
total unit in month = 56000/1000 = 56
total cost = 56×3 = 168 rs
An object has a mass of 785 g and a volume of 15 cm³. What is its density? (Give your answer in g/cm³ to 2 decimal places).
Answer:
denisity = 52.33 g/c[tex]m^{3}[/tex]
Explanation:
Density:
[tex]d = \frac{m}{v}[/tex]
We have that m = 785 and that v = 15 c[tex]m^{3}[/tex].
[tex]d = \frac{785}{15}[/tex]
d = 52.33 [tex]m^{3}[/tex]
The density of the object, calculated using the formula Density = Mass/Volume with the given mass of 785g and volume of 15cm³, is found to be 52.33 g/cm³.
Explanation:The subject in question is about determining the density of an object, which falls under the area of Physics. In physics, density is defined as mass per unit volume, and the formula for calculating density is Density (ρ) = Mass (m)/Volume (V). In the SI system, we often use grams per cubic centimeter (g/cm³) to express the density of solids and liquids.
To apply the formula to this question, we take the mass of the object, which is given as 785g, and then divide this by the volume of the object, given as 15cm³. Thus, the calculation becomes: ρ = 785g / 15 cm³.
The calculated density, to 2 decimal places, is 52.33 g/cm³. Therefore, the object in question has a density of 52.33 g/cm³.
Learn more about Density here:https://brainly.com/question/29775886
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Justine is ice-skating at the Lloyd Center. What is her final velocity if she accelerates at a rate of 2.0 m/s for 3.5 seconds?
Answer:
7 m/s
Explanation:
Acceleration, [tex]a=\frac {v-u}{t}[/tex]
Where v and u are the final and initial velocities of the Justine respectively, t is the time taken for Justin to attain final velocity.
Making v the subject then
v=at+u
Taking u as zero then
Substituting 3.5 for t, 2 as a then
v=3.5*2=7 m/s
4. How many planets are there in our solar system?
a. 9
b. 8
c. 12
d. 15
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Since Pluto is a dwarf planet, the correct option is B. 8
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12. A volcano erupts on Earth's surface causing a piece of rock with a mass of 95 kg to be ejected from rest to an acceleration of 9.5
m/s2. What force was exerted on the rock by the eruption? (TEK4D)
A 0IN
B 10.0N
C 95 N
D 902.5 N
Answer:
The force exerted on the rock by the eruption is, D. 902.5 N
Explanation:
Given data,
The mass of the rock ejected by the volcano, m = 95 kg
The acceleration of the ejected rock, a 9.5 m/s²
The force acting on an object is defined as the product of the mass and its acceleration. It is given by the relation,
F = m x a
= 95 x 9.5
= 902.5 N
Hence, the force exerted on the rock by the eruption is, F = 902.5 N
How does the gravity which pulls the moon and earth toward each other also affect the ocean?
the ocean creates tides accosiated with the ocean
Is the net force up 0.2 N and down 3 N balanced or not blanced
Answer:
Not balanced
Explanation:
The force pulling the object up is applying less force than the object pulling down, this means the object will move down
Answer:
Not balanced
Explanation:
I drop an egg from a certain distance and it takes the egg 3.74 seconds to reach the ground. How high up was the egg?
Answer:
The height from which the egg is dropped is 68.54 m.
Explanation:
Given:
Initial velocity of egg is, [tex]u=0\ m/s[/tex](Dropped means initial velocity is 0)
Time taken is, [tex]t=3.74\ s[/tex]
Acceleration experienced by egg is due to gravity, [tex]a=g=9.8\ m/s^2[/tex]
The height from which the egg is dropped is, [tex]d=?[/tex]
Now, we use Newton's equation of motion that relates the distance, initial velocity, time and acceleration.
So, we have the following equation of motion:
[tex]d=ut+\frac{1}{2}at^2[/tex]
Plug in all the given values and solve for 'd'. This gives,
[tex]d=0+\frac{1}{2}\times 9.8\times (3.74)^2\\\\d=\frac{1\times 9.8\times 13.9876}{2}\\\\d=\frac{137.078}{2}\\\\d=68.54\ m[/tex]
Therefore, the height from which the egg is dropped is 68.54 m.
Which structures protect the cell? Check all that apply.
- cell wall
- cell membrane
- mitochondrion
- nucleus
- ribosome
- Golgi body
Answer:
cell wall and cell membrane
Answer:
Cell wall and Cell membrane.
Explanation:
The cell membrane controls what goes in and out of the cell
Which element is this?
Answer:Silicon
Explanation:
You add up the protons and neutrons and then look at the element paper
> Science Sem 2 CR SHS1920
What can happen to solar radiation when it enters Earth's atmosphere? Select three options
It is absorbed by Earth.
It is reflected by clouds.
It is reflected by glacial ice.
It is condensed into visible light.
It is amplified by water molecules.
The following can happen to solar radiation when it enters Earth's atmosphere:
It is absorbed by Earth. It is reflected by clouds. It is reflected by glacial ice.Answer: Option A, B, and C
Explanation:
Solar radiation causes an abnormal effect in humans, if they are exposed directly. All the solar radiation emitted by the sun, does not hit us directly. The energy while reaching us passes through different levels of spheres.
Atmosphere contains nitrogen and oxygen molecules, which absorb some of the solar radiation. And some of it is reflected back by the clouds. And some of the remaining energy is absorbed by the surface of the earth. Likewise, almost 71% of the radiation is absorbed.
Answer: It is absorbed by Earth.
It is reflected by clouds.
It is reflected by glacial ice.
Explanation: Solar radiation is composed of electromagnetic waves that carry energy.
White or shiny surfaces usually reflect some waves (actually almost every surface reflects electromagnetic waves)
So some of the radiation is reflected by clouds or by glacial ice.
The bigest part is actually absorbed by Earth (this is why during the day the temperature increases, a biggest amount of radiation is being absorbed)
A copper sphere was moving at 40 m/s when it hit another object. This caused all of the KE to be converted into thermal energy for the copper sphere. If the specific heat capacity of copper is 387 J/(kg ⋅ C°), what was the increase in temperature?
0.23 C°
0.81 C°
1.3 C°
2.1 C°
Answer:
Temperature increase = 2.1 [C]
Explanation:
We need to identify the initial data of the problem.
v = velocity of the copper sphere = 40 [m/s]
Cp = heat capacity = 387 [J/kg*C]
The most important data given is the fact that when the shock occurs kinetic energy is transformed into thermal energy, therefore it will have to be:
[tex]E_{k}=Q\\ E_{k}= kinetic energy [J]\\Q=thermal energy [J]\\Re-employment values and equalizing equations\\\\\frac{1}{2} *m*v^{2}=m*C_{p}*dT \\The masses are canceled \\\\dT=\frac{v^{2}}{C_{p} *2} \\dT=2.1 [C][/tex]
The correct option is d. 2.1°C. The increase in temperature of the copper sphere was approximately [tex]\( 2.1 \)[/tex]°C, which corresponds to answer choice D).
Given:
- Initial kinetic energy (KE) of the copper sphere = [tex]\( \frac{1}{2} mv^2 \)[/tex]
- Specific heat capacity of copper, [tex]\( c = 387 \)[/tex] J/(kg·°C)
The entire kinetic energy is converted into thermal energy, [tex]\( Q = mc\Delta T \)[/tex], where [tex]\( \Delta T \)[/tex] is the increase in temperature.
1. Calculate the initial kinetic energy:
[tex]\[ KE = \frac{1}{2} mv^2 \][/tex]
2. Set up the equation equating kinetic energy to thermal energy:
[tex]\[ \frac{1}{2} mv^2 = mc\Delta T \][/tex]
3. Solve for [tex]\( \Delta T \)[/tex]:
[tex]\[ \Delta T = \frac{\frac{1}{2} mv^2}{mc} \][/tex]
4. Substitute the given values:
[tex]\[ \Delta T = \frac{\frac{1}{2} \times m \times (40)^2}{m \times 387} \][/tex]
5. Simplify the expression:
[tex]\[ \Delta T = \frac{800 \times m}{387 \times m} \]\[ \Delta T = \frac{800}{387} \]\[ \Delta T \approx 2.065 \ \textdegree C} \][/tex]
Rounding to one decimal place, the increase in temperature [tex]\( \Delta T \)[/tex] is approximately [tex]\( 2.1 \)[/tex]°C.
Therefore, the increase in temperature of the copper sphere was approximately [tex]\( 2.1 \)[/tex]°C, which corresponds to answer choice D).
A copper sphere was moving at 40 m/s when it hit another object. This caused all of the KE to be converted into thermal energy for the copper sphere. If the specific heat capacity of copper is 387 J/(kg ⋅ C°), what was the increase in temperature?
a. 0.23 C°
b. 0.81 C°
c. 1.3 C°
d. 2.1 C°