Answer:
Option D
Explanation:
The work done can be given by the mechanical energy used to do work, i.e., Kinetic energy and potential energy provided to do the work.
In all the cases, except option D, the energy provided to do the useful work is not zero and hence work done is not zero.
In option D, the box is being pulled with constant velocity, making the acceleration zero and thus Kinetic energy of the system is zero. Hence work done in this case is zero.
Answer:
A force is a push or pull upon an object resulting from the object's interaction with another object. Whenever there is an interaction between two objects, there is a force upon each of the objects.
Explanation:
Answer:
a) No. If air resistance is ignored the acceleration of the ball is the same at each point on its flight.
(b). No. As long as the air resistance is negligible, the acceleration of the ball at the top of its flight different from its acceleration just before it lands.
Explanation:
This constant, similar acceleration is called the acceleration due to gravity and it is the acceleration of a body due to the influence of the pull of gravity alone.
Every object on the surface of the earth regardless of its mass is pulled towards the centre of the earth, especially when in flight. Whether flying upwards, or coming downwards, the pull of attraction towards the surface of the earth is the same!
Yes. It's approximately the same, but not exactly.
The weight of an object 7 miles above the Earth's surface (the gravitational force on it) is about 0.35% less than it is down on the surface.
Answer:
To explain what happens with the ball we must remember the Law of Conservation of Energy.
This law states that the energy can be neither created nor destroyed only converted from one form of energy to another.
Then,
At the top of the hill, the potential energy is maximum and the kinetic energy equals to zero.
When the ball starts to roll down the potential energy will be lower and the kinetic energy will have a low value.
At the middle of the hill, both energies have the same values.
At the end of the hill, the potential energy will be equal to zero and the kinetic energy will be maximum.
<em>Correct me if I'm wrong...</em>
<em>hope it helps...</em>
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