Acar skids 18 m on a level road while trying to stop before hitting a stopped car in front of it. the two cars barely touch. the coefficient of kinetic friction between the first car and the road is 0.80. a policewoman gives the driver a ticket for exceeding the 35 mi/h speed limit.
determine the initial speed of the car.

Anybody wanna ? (picture included? )

You are driving directly behind a pickup truck, going at the same speed as the truck. a crate falls from the bed of the truck to the road. (a) will your car hit the crate before the crate hits the road if you neither brake nor swerve? (b) during the fall, is the horizontal speed of the crate more than, less than, or the same as that of the truck?

Two resistors r1 and r2 may be connected either in series or parallel across an ideal battery with emf ε. we desire the rate of energy dissipation of the parallel combination to be 8.75 times that of the series combination. if r1 = 105 ω, what are the (a) smaller and (b) larger of the two values of r2 that result in that dissipation rate?