Question

A particle is moving in a xy plane with y = 2x and Vx = 2 – t. Find Vy at time t = 3 second. 

(A) 2 ms^–1 

(B) – 3 ms^–1 

(C) + 3 ms^–1 

(D) – 2 ms^–1

Answer 1

Correct option: (D) – 2 ms^–1

Explanation:

y = 2x

Vx = 2 – t

(dy / at) = Vy = 2 (dx / dt)

Vy = 2Vx

Vy = 2(2 – t)

Vy = 4 – 2t

at t = 3 sec, Vy = 4 – 6 = – 2 m/s.