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2 years ago

Describe a scenario when you could use energy but not do any work.

Physics

1 answer:

Harlamova29_29 [7]2 years ago

4 0

Answer:

When you don't move, you still use energy. This energy is called potential energy, or, stored energy.

When you don't move or do work, you can use energy.

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Technician a says that the water pump is a centripetal pump. technician b says that centripetal force is the outward force that

Vaselesa [24]

Technician A is correct about the water pump being a centripetal pump and the definition of the centripetal force given by technician B is wrong. The force that happens on a body moving in a circular path and move towards the centre to which the body is moving is called as centripetal force. So itâ€™s not an outward force.

3 0

3 years ago

Find the voltage drop (in volt) along a 93.4 meter long 10 gauge copper wire carrying acurrent of 72.5 A. The diameter of a 10 g

Sophie [7]

Answer: 5.41 V

Explanation:in order to explain this result we have to use the Ohm law given by:

ΔV=R*I where R is the resistance which is equal R= ρ*L/A . ρ is the resistivity, L the length of the wire and A is the cross section. I is the current.

Then we have

ΔV=ρ*L*I/A= 1.68 * 10^-8 Ωm*93.4 m*72.5A/2.1* 10^-5 m^2=5.41 V

3 0

3 years ago

A 210-kg woorden raft floats on a lake. When a 75-kg man stands on the raft, it sinks 5.0 cm deeper into the water. When he step

GaryK [48]

Answer:

A: The frequency of the vibration is 1.3329 Hz

B: The total energy of the vibration is 18.39375 J

Explanation:

The force of the man his weight causes the raft to sink, and that causes the water to put a larger upward force on the raft. This extra force is a restoring force, because it is in the opposite direction of the force put on the raft by the man. Then when the man steps off, the restoring force pushes upward on the raft, and thus the raft – water system acts like a spring, with a spring constant found as follows:

k= F/x = ((75 kg) * (9.81 m/s²))/(5*10^-2 m) = 14715 N/m

The frequency of the vibration is determined by the spring constant (k) and the mass of the raft (210kg).

fn = 1/2π * √(k/m) = 1/2π * √(14715 / 210) = 1.3329 Hz

The frequency of the vibration is 1.3329 Hz

b)

Since the gravitational potential energy can be ignored, the total energy will be :

Etot = 1/2 k* A² = 1/2 * (14715 )*(0.05)² = 18.39375 J

The total energy of the vibration is 18.39375 J

7 0

2 years ago

Pluto was first observed in 1930, and its largest moon, Charon, was discovered in 1978. A few years after Charon’s discovery, as

mylen [45]

Answer:

The average densities of both matches the expected density for objects made from water ice.

Explanation:

Charon's density is 1.2 to 1.3 g / cm3, while Pluto's density is 1.8 to 2.1 g / cm3. This was discovered in many researches and measurements of these two celestial bodies, with the objective of understanding them and promoting efficient scientific knowledge.

With the measurements of the average densities between pluto and Charon it was possible to conclude several statements about them. Firstly, it is possible to see that the two formed independently and at different times, in addition to indicating the existence of few rocks in charon, which is consistent with the average density of objects made mostly of water ice.

8 0

3 years ago

Suppose astronomers built a 150-meter telescope. how much greater would its light-collecting area be than that of the 10-meter k

Dennis_Churaev [7]

Almost all telescopes have a circular mirror. The area of a circle is proportional to $r^2$ where $r$ is the radius of the circle, the constant of proportionality being $4\pi$
$S =4\pi r^2$
Therefore the area of 150 meter telescope would be
$S_1/S_2=(r_1/r_2)^2 =(75/5)^2 =15^2=225$
times bigger than the area of the smaller (10 meter) telescope.

6 0

2 years ago