Force Scenario Solutions

Joe Cox

Brookwood High School

Scenario 1

• A block of mass 5 kg is setting on a frictionless table. It is connected by a massless string to a 3 kg mass, which is hanging from a massless-frictionless pulley at the edge of the table.

Scenario 2

• Repeat the problem above if the coefficient of friction between the table and the 5 kg block is .3.

Scenario 3

• The engines of a 100 N rocket exert a 1,000N thrust for the first ten seconds of flight.

Scenario 4

• Repeat the problem above after engines of the rocket turn off.

Scenario 5

• A braking force of 10,000 N slows a car traveling at a speed of 30 m/s.

Scenario 6

• A block slides down a 30o frictionless incline.

Scenario 7

• Repeat the problem above if friction is present and the block slides at constant velocity.

Scenario 8

• A block slides at constant velocity on a frictionless horizontal surface.

Scenario 9

• A block slides at constant velocity on a horizontal surface where friction is present.

Scenario 10

• A block with an initial velocity slides up a 30o incline where friction is present.

Scenario 11

• A block with a mass 10kg is on a frictionless surface. An 8 kg block is placed to the left of the 10 kg block so that the two blocks are touching each other. A 36 N force pushes the 8 kg block to the right.

Scenario 12

• A block of mass M is connected by a string to a block with a mass of m. A second horizontal string is attached to m which pulls both blocks across a frictionless horizontal surface with an acceleration, a.

Scenario 13

• A lawn mower is pushed across a lawn at a constant velocity by applying a force, F along the handle of the lawn mower that makes an angle of 30o with the horizontal.

Scenario 14

• A child pulls a red wagon at a constant velocity by applying a force, F along the handle that makes a 45o to the horizontal.

Scenario 15

• A cable is connected to a hook of mass m. The hook is attached to a rope that is connected to a crate of mass M. The motor that pulls the cable upward exerts the minimum force necessary to lift the load.

Scenario 16

• An elevator of weight W accelerates downward with acceleration, a.

Scenario 17

• A crate sits in the back of a truck that is accelerating to the right. The crate does not move relative to the bed of the truck. Draw the free body diagram and sum the forces for the crate only.

Scenario 18

• A pendulum is pulled back 15o from the vertical and released. Draw the free body diagram and sum the forces when the pendulum bob is at its lowest position.

Scenario 19

• A pendulum is pulled back 15o from the vertical and released. Draw the free body diagram and sum the forces when the pendulum bob is at its highest position.

Scenario 20

• A 200 N sign hangs from two cables that make an angle of 50o with each other.

Scenario 21

• A cable that makes an angle of 30o with the horizontal and a second cable that is completely horizontal support a 100kg load.

Scenario 22

• A block of mass M and a block of mass m are hanging from opposite sides of a massless, frictionless pulley. (M>m)

Scenario 23

• A block of mass M is pulled up a 20o incline with friction by a string that passes over a light frictionless pulley at the top of the incline. The string is attached to a block of mass m that hangs vertically from the pulley. (M>m)

Scenario 24

• Block A rests on top of Block B which is sitting on a table.

Scenario 25

• A car goes around a curve of radius, R at a constant speed, v.

Scenario 26

• A car goes around a frictionless curve banked at 20o.

Always draw the banked curve at a very small or very large angle. As a result it is obvious which angle in the component triangle is equal to the angle of the bank.

Scenario 27

• A bucket attached to a string is at the top of a vertical circle.

Scenario 28

• A bucket attached to a string is at the bottom of a vertical circle.

Scenario 29

• A person riding a roller coaster feels weightless at the top of a vertical loop.

Scenario 30

• A flying toy is hanging from the ceiling as it flies in a horizontal circle. At any instant the string connecting the toy to the ceiling makes an angle of 30o with the vertical.