Question

A car with a mass of 1.1 x10 to the third power killograms hits a stationary truck with a mass of 2.3kg x10 to the third power from the rear ean. The initial velocity of the car is +22.0 meters/second. After the collision the velocity of the car is -11.0 meters/second. What is the velocity of the truck after this elastic collision.

Answer 1

v2f = +15.8 m/s

Step-by-step explanation:

Conservation law of linear momentum:

m1v1i + m2vi2 = m1v1f + m2v2f

Given:

m1 = 1.1 × 10^3 kg

m2 = 2.3 × 10^3 kg

v1i = +22.0 m/s

v2i = 0

v1f = -11.0 m/s

v2f = ?

Re-arranging the conservation law, we get

m1v1i = m1v1f + m2v2f

Solving for v2f,

m2v2f =m1(v1i - v1f)

or

v2f = m1(v1i - v1f)/m2

= (1.1 × 10^3 kg)(22.0 m/s - (-11.0 m/s))/(2.3 m/s)

= (1.1 × 10^3 kg)(33.0 m/s)/(2.3 × 10^3 kg)

= +15.8 m/s