Answer:
4 m/s
Step-by-step explanation:
From the question given above, the following data were obtained:
Mass of 1st cart (m₁) = 20 kg
Initial velocity of 1st cart (u₁) = +6 m/s
Mass of 2nd cart (m₂) = 30 kg
Finally velocity of both cart (v) = 0 m/s
Initial velocity of 2nd cart (u₂) =?
The initial velocity of the 2nd cart can be obtained as follow:
m₁u₁ – m₂u₂ = v(m₁ + m₂)
(20 × 6) – (30 × u₂) = 0 (20 + 30)
120 – 30u₂ = 0(50)
120 – 30u₂ = 0
Collect like terms
– 30u₂ = 0 – 120
– 30u₂ = – 120
Divide both side by –30
u₂ = –120 / –30
u₂ = 4 m/s
Thus, the 2nd (i.e the 30 kg) cart was initially moving with a velocity of 4 m/s.