When an item is raised, the work is done in opposition to gravity. When an item is worked on, energy is transmitted to it, and it develops gravitational potential energy. If the same thing falls from that height, gravity must do the same amount of effort to bring it back to the Earth's surface.
Answer: The ball (option A)
Explanation: change in momentum is defined by the formulae m(v - u) where m = mass of object, v = final velocity and u = initial velocity.
For the ball, it hits the ground and bounces back with the same speed, that's final velocity equals initials (v = - u)
Change in momentum = m( -u- u) = m(-2u) = m(-2u) = -2mu
For the clay, it final velocity is zero since it sticks to the floor, hence (v =0)
m(v - u) = m(0 - u) = - mu.
-2mu (change in momentum from the ball) is greater than - mu ( change in momentum of clay)
<span>D. The speed of light, traveling in a vacuum, will not change if the light source is moving.
The speed of light in a vacuum is always constant regardless of the speed the source or you are travelling at.</span>
Reptiles, such as snakes and lizards, are cold-blooded animals. This means that they do not have the ability to control their body heat. For this reason, they often lay out in the sun to warm up. If their enviornent is cold they obtain that body temperature. They are very slow in colder environments.In cold weather these animals have a very difficult time moving because their muscles are very cold. Without heat in their environment, they cannot warm them up.
