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

1.49 m/s East

Step-by-step 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* 24.9 m/s +(3329 Kg * -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`