Question

A 912 kg truck, moving forward at 59.6 km/h, collides head-on into a stationary 618 kg car. If they stick together right after the impact, what is the magnitude of the velocity in m/s

Answer 1

Given:

The mass of the truck is m1 = 912 kg

The initial velocity of the truck is

`\begin{gathered} v_(1i)=\text{ 59.6 km/h} \\ =59.6*\frac{1000\text{ m}}{3600\text{ s}} \\ =\text{ 16.556 m/s} \end{gathered}`

The mass of the car is m2 = 618 kg

The initial velocity of the car is

`v_(2i)=\text{ 0 m/s}`

To find the velocity of the truck and car after the collision.

Step-by-step explanation:

According to the conservation of momentum,

`\begin{gathered} m1v_(1i)+m1v_(2i)=\text{ \lparen m1+m2\rparen v}_f \\ v_f=(m1v_(1i)+m1v_(2i))/(m1+m2) \end{gathered}`

On substituting the values, the magnitude of velocity after the collision will be

`\begin{gathered} v_f=\frac{(912*\text{ 16.556\rparen -\lparen618}*0\text{\rparen }}{(912+618)} \\ =\text{ 9.86 m/s} \end{gathered}`

Thus, the magnitude of velocity after the collison is 9.86 m/s