Question

how fast should a man of mass 50kg run so that his kinetic energy be 625j?

Answer 1

as k=1/2mv×v

so, 625=1/2×50v×v

v×v=625/25
v×v=25
v=5m/s

Answer 2

Answer:

Explanation:

Solution :-

Given :-

Mass, m = 50 kg

Kinetic Energy, K.E = 625 J

To Calculate :-

Velocity, v = ??

Formula to be used :-

1/2mv² = v² = 2 × K.E/m

v² = 2 × 625/50

v² = 1250/50

v² = ± 5 m/s

We do not consider the negative sign since it indicates the direction of motion only.