Question
The coefficient of kinetic friction between the tires and the road for an automobile is 0.8. What is the stopping distance for a car of mass 2,000 kg, travelling at 20 m/s? 25.5 m. 52.6 m. 46.3 m. 83.8 m A Hooke's law spring is, compressed 0.2 m from equilibrium. The spring constant is 800 N/m. It is then released driving a 2 kg sphere along a frictionless surface. What is the speed of the sphere? A car hits a wall and is brought to rest in 0. 2 seconds. The mass of the car in 1,200 kg, and it was travelling with a speed of 15 m/s. What is the magnitude of the average force imparted to the car? 60,000 N. 120,000 N. 90,000 N. 40N. A rail car of mass 20,000 kg is travelling east with a speed of 12 m/s. It collides with a 10,000 kg car which is at rest. They link together. What is the speed of the combined cars after collision.
Explanation / Answer
17.) 1/2mV02 - Wnc = 0 Wnc = 400,000 J Wnc = distance x normal force x Normal force = mg Wnc = dmg distance = 25.5m 18.) 1/2kx2 = 1/2mV2 V= 4 m/s 23.) F =ma a = V2 - V1 / t2 -t1 a = -75 m/s^2 F = 1,200 x -75 F = 90,000N 24.) m1 = 20,000 m2 = 10,000 V1 = 12 V2 = 0 m1v1 = (m1 + m2)v v = 8m/s Cheers Billy a = -75 m/s^2 F = 1,200 x -75 F = 90,000N 24.) m1 = 20,000 m2 = 10,000 V1 = 12 V2 = 0 m1v1 = (m1 + m2)v v = 8m/s Cheers Billy