Question

A 2444 kg car moving at 24.9 m/s east collides with a 3329 kg truck moving at 15.7 m/s west. After the collision the two vehicles stick together, what is their combined velocity

Answer 1

Answer:

1.49 m/s East

Explanation:

From the law of conservation of momentum, the sum of initial momentum equals the sum of final momentum

Momentum, p=mv where m is the mass and v is the velocity

$m_1v_1+m_2v_2=(m_1+m_2)v_c$ where $v_c$ is the common velocity, $v_1$ and $v_2$ are velocities of car moving East and West respectively, $m_1$ and $m_2$ are masses of car moving East and West respectively

Taking East direction as positive then west as negative then substituting 2444 Kg for  $m_1$ and 3329 Kg for $m_2$, also 24.9 m/s for $v_1$ and -15.7 m/s for $v_2$

$2444 kg\times 24.9 m/s +(3329 Kg \times -15.7 m/s)=(2444 Kg + 3329 Kg)V_c$

$5773 kg v_c=8590.3  Kg. m/s$

$v_c=\frac {8590.3  Kg. m/s}{5773 Kg}=1.488013165  m/s\approx 1.49 m/s$