Question

A 3.00-kg object has a velocity 16.00 i ^ 2 2.00 j ^2 m/s.

Answer 1

Answer:

390 J

Explanation:

m = 3 kg

u = 16 i + 2 j

(a) Magnitude of velocity = $\sqrt{16^{2}+2^{2}}$ = 16.1245 m/s

KEi = 1/2 m v^2 = 0.5 x 3 x 16.1245 = 390 J

(b) v = 18 i + 14 j

Magnitude of velocity =  $\sqrt{18^{2}+14^{2}}$ = 22.804 m/s

KEf = 1/2 m v^2 = 0.5 x 3 x 22.804 = 780 J

According to the work energy theorem

Work done = change in KE = KEf - KEi = 780 - 390 = 390 J