Question

1 A stone of weight 0.25 kgf is projected vertically
upward such that it attains a height of 40 m.
Calculate the amount of energy in the stone at
the highest point. [Take 1 kgf = 10 N] [100 J]
:.

2 A boy of mass 50 kg climbs stairs by spending
1200 J of energy. How high does the boy climb
up? [Take g = 10 ms-2]
[2.4 m]​

Answer 1

Answer:

1)

mass of stone is 0.25kg

height of stone is 40m

energy stored=PE

PE=mg

= 0.25×10×40

=100j