Question

a 2,000 kg truck moving at 15 m/s collides head - on and sticks to a 1,000 kg car that is initially at rest. what is their final velocity? a. 5 m/s b. 10 m/s c. 15 m/s d. 20 m/s

Explanation:

Step1: Apply the law of conservation of momentum

The formula for conservation of momentum is \(m_1v_1 + m_2v_2=(m_1 + m_2)v\). Here, \(m_1 = 2000\space kg\), \(v_1=15\space m/s\), \(m_2 = 1000\space kg\), and \(v_2 = 0\space m/s\) (since the car is initially at rest).
Substitute the values into the formula: \((2000\times15)+(1000\times0)=(2000 + 1000)v\)

Step2: Solve for \(v\)

First, calculate the left - hand side: \(2000\times15+0=30000\). The right - hand side is \(3000v\).
So, \(3000v = 30000\). Then \(v=\frac{30000}{3000}=10\space m/s\)

Answer:

B. \(10\space m/s\)