Question

A ball of mass 0.4 kg is thrown vertically upward with a velocity 14 m/s. Calculate its kinetic energy and potential energy after 1 s.

Answer 1

v = u + at

= 14 + 10 × 1

= 24 m/s

KE = \(\frac{1}{2}\) mv²

= 1/2 × 0.4 × 24

= 115.2 J

S = ut + 1/2 at²

= 14 × 1 + 1/2 × 10 × 1²

= 14 + 5 = 19 m

E = mgh = 0.4 × 10 × 19 = 76 J