Answer:
The initial velocity of the car is V1= 5.58 m/s = 20.12 km/h
Explanation:
m1= 1689 kg
v1= ?
m2= 2000kg
v2= 17 km/h = 4.72 m/s
by the conservation of quantity of movement :
m1*v1 = m2*v2
v1= m2*v2 / m1
v1= 5.58 m/s = 20.12 km/h
Answer:
5.16 m/s
Explanation:
mass of car, m1 = 1689 kg
mass of truck, m2 = 2000 kg
Velocity of truck after collision, v2 = 17 km/h = 4.72 m/s
Let the initial velocity of car is u1.
initial velocity of truck, v1 = 0
velocity of car after collision, v1 = ?
Use conservation of momentum
m1 x u1 + m2 x u2 = m1 x v1 + m2 x v2
1689 x u1 + 2000 x 0 = 1689 x v1 + 2000 x 4.72
1689 u1 = 1689 v1 + 9444.4 .... (1)
As the collision is elastic, so coefficient of restitution is 1.
Use the formula for the coefficient of restitution.
[tex]e=\frac{v_{1}-v_{2}}{u_{2}-u_{1}}[/tex]
e = 1
v1 - 4.72 = 0 - u1
v1 = 4.72 - u1
Substitute the value of v1 in equation (1)
1689 u1 = 1689 (4.72 - u1) + 9444.44
1689 u1 = 7972.08 - 1689 u1 + 9444.44
3378 u1 = 17416.52
u1 = 5.16 m/s
Thus, the speed of car before collision is 5.16 m/s.
