A 3.0 kg mass body has an initial velocity v0 = (6.0 i - 2.0 j) m/s.

Question

(a) What is the initial kinetic energy?

(b) Determine the value of the final kinetic energy if its velocity changes to v0 = (8.0 i + 4.0 j)?

Answer 1

(a)

K = mv₀² / 2

v₀² = v_0x² + v_0y²

m = 3.0 kg

v_0x = 6.0 m/s

v_0y = -2.0 m/s

Plug in the numbers and get K in joules.

(b)

Work the same way as part (a), but with

v_0x = 8.0 m/s

v_0y = 4.0 m/s