Question

The velocity of a mass of 5 kg after falling a height of 5 metre from rest would be

Answer 1

Not sure but this approach can be handy :

Potential energy from height 5 m

P.E = m g h

= > P.E = 5 kg × 10 m/s² × 5 m

= > P.E = 25 kg m × 10 m/s²

= > P.E = 250 kg m²/s²

= > P.E = 250 J

We know that potential energy at the height = kinetic energy while falling .

K = 1/2 m v²

K = P = 250 J

1/2 m v² = 250 J

= > 1/2 × 5 × v² = 250 J

= > v² = 250 × 2/5

= > v² = 50 × 2

= > v² = 100

= > v = 10 m/s

ANSWER:

The velocity is 10 m/s