Force and Friction on a CratePro Problems > Physics > Motion and Forces > Linear Motion > Force
Force and Friction on a Crate
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 µk is zero?
SolutionIn order to make it feasible for teachers to use these problems in their classwork, no solutions are publicly visible, so students cannot simply look up the answers. If you would like to view the solutions to these problems, you must have a Virtual Classroom subscription.
Luke Skywalker's X-Wing
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?
Hockey Stick and Puck
A hockey stick travels backward 11.0 cm while intercepting a 0.140 kg puck. How much force did the stick exert on the puck to bring the puck from 35.0 m/s to rest?
A 5.0 kg missle is projected from rest to a speed of 4.5 x 103 m/s. How much time is required to do this by a net force of 5.3 x 105 N?
Cart with Groceries
1.A horizontal force of 10N is applied to a 30 kg cart on a level floor.
- How far will it move in 3.0s, starting from rest? Ignore friction.
- How far will it move in 3.0s if 30N of groceries is added to the cart first?
Car and Motorcycle
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?
M1 and M2
A mass, m1, accelerates at 3 m/s2 when a force, F, is applied. A second mass, m2, accelerates at 1.0 m/s2 when F is applied to it.
- Find the value of the ratio m1/m2.
- Find the acceleration of the combined mass ( m1 + m2) under the action of the force, F.
Braking to a Stop
A 1000-kg car moving north at 100km/h brakes to a stop in 50m. What are the magnitude and direction of the force?
Car with Passengers
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?
Howard doesn't Move
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.
Force on Two Objects
If a force accelerates 4.5 kg at 40 m/s2, that same force would accelerate 18 kg by how much?