Answer:
work done = ( force × displacement)
(a)The force acting on the block is it's self weight and displacement is equal to height of the tower.
work done by gravity = (250 × 10) = 2500 joule
(b) The work done by gravity 2500 joule is transferred to the object in the form of it's kinetic energy.
If a constant force is applied on a body, the body moves with constant acceleration.
The type of heat that the Sun emits is called UV (Ultra Violet) rays. This is a natural type of heat, but it can also be dangerous if you expose yourself to too much UV heat, causing "sunburns", or even skin cancer.
The answer is A. Force is equal to mass x acceleration. The acceleration due to gravity is a constant so multiplying the mass by 2 would double the force.
Gravitational potential energy can be described as m*g*h (mass times gravity times height).
Originally,
15kg * 9.8m/s^2 *0.3 m = 44.1 kg*m^2/s^2 = 44.1 Joules.
After it is moved to a 1m shelf:
15kg * 9.8m/s * 1 = 147 kg*m^2/s^2= 147 Joules.
To find how much energy was added, we subtract final energy from initial energy:
147 J - 44.1 J = 102.9 Joules.