If the coefficient of kinetic friction between a 35 kg crate and the floor is .30, what horizontal force is required to move the crate at a steady speed across the floor? What horizontal force is required if µ_k is zero?

A car accelerates from 10 m/s to 50 m/s while traveling 400 m. The mass of the car is 1500 kg. What force was applied to the car?

Four passengers with mass 85 kg apiece are added to the problem above, how much would that change the force required?

A 6000 kg tractor rests on a flatbed, held in place by chains. The chains provide a maximum horizontal force of 8000 N. When the flatbed is traveling 20 m/s, what is the minimum stopping distance if the chains are not to break?

A 1000-kg car moving north at 100km/h brakes to a stop in 50m. What are the magnitude and direction of the force?

 

An elevator has a mass of 2,000 kg.  An upward force of 21,000 Newtons is applied to the elevator. The elevator travels up 50 floors, and each floor is 2.5 meters tall, with a 20 centimeter gap between floors. How long does it take the elevator to arrive, and at what speed will it be traveling?

A force is applied to a 1000 kg car, and causes the car to accelerate from 0 m/s to 25 m/s while traveling 200 m. The same force is applied to a 600kg motorcycle.  How far will the motorcycle travel while accelerating from 10 m/s to 40 m/s?

After Luke Skywalker got his X-Wing fighter out of the swamp on Dagobah, he wanted to make it fly. The mass of the ship is 5,000 kg. Luke applies (using the force) an upward force of x Newtons. Yoda, who doesn't want Luke to get too confident, applies a downward force which is two-thirds of Luke's force.

Luke's Skywalker X-Wing fighter lifts off to a height of 2 km in 5 seconds. How much force did Luke apply?

Howard is standing in the middle of a skating rink (we'll assume no friction), and his four friends Alice, Bernie, Christopher, and David approach him from each of the four compass directions - north, east, south, and west, respectively.

Alice pushes on Howard with a force of x + 20 Newtons. Bernie pushes on him with a force of 2x + y Newtons. Christopher pushes on him with a force of 2x - y Newtons, and David pushes with a force of 5y Newtons.

Howard, though being pushed from all directions, does not move. Calculate the forces being applied in all four directions.

1.A horizontal force of 10N is applied to a 30 kg cart on a level floor. 

1. How far will it move in 3.0s, starting from rest? Ignore friction. 
2. How far will it move in 3.0s if 30N of groceries is added to the cart first?

A 50 slug car can accelerate from 0 to 50 ft/s while traveling 1000 feet. The car then stops, and a passenger gets in. Now the car can accelerate from 0 to 50 ft/s while traveling 1050 feet. What is the weight of the passenger?