A girl of mass 35 kg climbs up from the first floor of a building at a

1.	A girl of mass 35 kg climbs up from the first floor of a building at a height 4m above the ground to the third floor at a height 12m above the ground. What will be the increase in her gravitational potential energy ? (g = 10 ms-2 ).
Answer» Gravitational potential energy at 1st floor = mgh1 = 35 × 10 × 4 = 1400 J Potential energy at third floor = mgh₂ = 35 × 10 × 12 = 4200 J Increase in potential energy = 4200 – 1400 = 2800 Joule.

A girl of mass 35 kg climbs up from the first floor of a building at a height 4m above the ground to the third floor at a height 12m above the ground. What will be the increase in her gravitational potential energy ? (g = 10 ms-2 ).

Answer»

Gravitational potential energy at 1st floor = mgh1 = 35 × 10 × 4 = 1400 J

Potential energy at third floor = mgh₂

= 35 × 10 × 12 = 4200 J

Increase in potential energy = 4200 – 1400 = 2800 Joule.