Homework SourseA car of mass 3567 kg is speeding down the road at a speed o
A car of mass 3567 kg is speeding down the road at a speed of 4.3 m/s. Just as it passes a 1890 kg cop car idling, the cop car accelerates at a rate of 4.6 m/s^2 to catch up with the car.
A.) After 6.4 seconds how far is the center of mass of the two cars from where the cop car was idling?
B.) after 2.4 seconds how fast is the center of mass of the two cars moving?
A car of mass 3567 kg is speeding down the road at a speed of 4.3 m/s. Just as it passes a 1890 kg cop car idling, the cop car accelerates at a rate of 4.6 m/s^2 to catch up with the car.
A.) After 6.4 seconds how far is the center of mass of the two cars from where the cop car was idling?
B.) after 2.4 seconds how fast is the center of mass of the two cars moving?
A.) After 6.4 seconds how far is the center of mass of the two cars from where the cop car was idling?
B.) after 2.4 seconds how fast is the center of mass of the two cars moving?
Solution
A)
using the equation of motion:
v = u + at
For the cop car,
u = 0
a = 4.6 m/s2
t = 6.4 s
So, v = 4.6*6.4 = 29.44 m/s
So, the speed of center of mass = (3567*4.3+1890*29.44)/(3567+1890)
= 13 m/s <-----------answer
B)
Similarly after 2.4s,
v = 0 + 4.6*2.4 = 11.04 m/s
So, speed of center of mass:
= (3567*4.3+1890*11.04)/(3567+1890)
= 6.63 m/s <--------answer
