Force Bonus Problems
1.) A shopper in a supermarket pushes a loaded 32 kg cart with a horizontal force of 12 N. a.) How far will the cart move in 3.5 s, starting from rest? (disregard friction)
2.) A block with a mass of 5 kg is held in equilibrium on an incline of angle 30 degrees by the horizontal force, F, as shown in the figure above. A.) Find the magnitude of F. b.) Find the normal force exerted by the incline on the block.
3.) Find the force exerted by each cable to support the 625 N bag in the figure 4.32.
4.) A 4 kg block is pushed along the ceiling with a constant applied force of 85 N that acts at an angle of 55 degrees with the horizontal. The block accelerates to the right at 6 m/s2. Determine the coefficient of kinetic friction between the block and the ceiling.
5.) A 35 kg box rests on the back of a truck. The coefficient of static friction between the box and the truck bed is .3. a.) When the truck accelerates forward, what happens to the box? B.) Find the maximum acceleration the truck can have before the box slides.
6.) A 3 kg block starts from rest at the top of a 30 degrees incline and slides 2 m down the incline in 1.5s. a.) Find the acceleration of the block. B.) Find the coefficient of kinetic friction between the block and the incline. C.) Find the frictional force acting on the block. D.) Find the speed of the block after it has slid a distance of 2 m.
7.) A hockey puck is hit on a frozen lake and starts moving with a speed of 12 m/s. Exactly 5 s later, its speed is 6 m/s. a.) What is its average acceleration? B.) What is the average value of the coefficient of kinetic friction between puck and ice? C.) How far does the puck travel during this 5 s interval?
9.) Refer to the diagram in figure 4-37 to answer the following questions. A.) What is the minimum force of friction between the table and the 150 N block required to hold both blocks in equilibrium? B.) What would the coefficient of static friction between the 150 N block and the table have to be to ensure that both blocks would be held in equilibrium?
10.) The parachute on a race car that weighs 8820 N opens at the end of a quarter mile run when the car is traveling 35 m/s. What total retarding force must be supplied by the parachute to stop the car in a distance of 1100m?
11.) A block is projected up a frictionless inclined plane with initial speed of 3.5 m/s. The angle of incline is 32 degrees.
a.) how far up the plane does the block go?
b.) How long does it take to get there?
c.) What is its speed when it gets back to the bottom?
12.) A rocket and its payload have a total mass of 5*104 kg. How large is the force produced by the engines when the rocket is
a.) hovering over the launch pad just after ignition
b.) Accelerating upward at 20 m/s2
13.) A 52 kg circus performer is to slide down a rope that will break if the tension exceeds 425 N.
a.) What happens if the performer hangs stationary on the rope?
b.) At what magnitude of acceleration does the performer just avoid breaking the rope?
14.) A loaded penguin sled weighing 80 N rests on a plane inclined at angle 20 degrees. Between the sled and the plane, the coefficient of static friction is .25, and the coefficient of kinetic friction is .15.
a.) What is the least magnitude of a force, applied parallel to the plane of the incline, that will prevent the sled from slipping down the plane?
b.) What is the minimum magnitude of the force that will start the sled moving up the plane?
c.) What value of the force is required to move the sled up the plane at constant velocity?