A child is playing on a trampoline jumping up and down. She is very skillful in playing on the trampoline, and at every bounce she reaches the same height always. Which of the followings is correct? (A) The elastic potential energy of the trampoline is constant and never changes while she is playing.
(B) Her gravitational potential energy is constant and never changes while she is playing.
(C) Her gravitational potential energy changes constantly, and reaches maximum when she reaches the maximum height.
(D) The elastic potential energy of the trampoline changes constantly, and reaches maximum when she reaches the maximum height.

C

Explanation:

Her gravitational potential energy changes constantly, and reaches maximum when she reaches the maximum height.

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-a geothermal heat pump system consists of a heat pump, an air delivery system (ductwork), and a heat exchanger-a system of pipes buried in the shallow ground near the building

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weight of the box is given as

here this is placed on the inclined of angle 42 degree

now this weight will have two components one is along the incline other is perpendicular to it

so here we need to apply a force parallel to incline opposite to its component of weight

so here the component of weight is given as

here we have

so it requires 75 n force to move it upwards