Question

an object of mass 40kg is raised to a height of 5m above the ground. what is its potential energy? if the object is allowed to fall, find its kinetic energy when it is half-way down
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Answer 1

Answer:

Answers and steps in the pic..hope u can understand the method

Answer 2

Answer: Given

Mass of the object = 40kg

Height = 5m

Find out

We need to find Potential energy and also  its kinetic energy when it is half-way down

Solution

Potential energy (U)  is given by the expression,

U= mgh

Where,

m = Mass of the object

h = Vertical displacement

g = Acceleration because of gravity = 9.8 ms-2

W= 40 X 9.8 X 5

W= 1960 J

At half-way down, the Kinetic energy of the item are going to be

At this time, the item has an equal quantity of potential and K.E.

This can be due to law of conservation of energy. Hence, half-way down, the K.E. of the object can be calculated as

1960 J/ 2 = 980 J

half way down = 980 J