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Figure 1


Figure 2


Figure 3


Figure 4


Figure 5


Figure 6

Phys 211 Final Practice Problems

  1. The length of an object is divided into 3 parts. Each part is measured to determine the total length. The first part is 3.10x10-3 m long. The second part is 0.161 m long, and the third part is 12.3 m long.
    1. What is the total length of the object?
    2. How many significant digits should be used to describe the total length?
  2. How many seconds are there in September?
  3. A wrecking ball is hanging at rest from a crane when suddenly the cable breaks. The time it takes the ball to fall halfway to the ground is 3.1 s. Find the time it takes for the ball to fall from rest all the way to the ground.
  4. An object is moving with a speed of 5.00 m/s in the x direction and a speed of 4.00 m/s in the negative y direction. What is the magnitude and direction of its velocity?
  5. A 450 N box is connected to a drum by a weightless cord as shown in Figure 5. As the box falls the cord unwinds from the drum causing it to turn. The drum has a 0.50 m radius and a moment of inertia of 20 kg*m2. Find the acceleration of the box.
  6. A block of mass 50 kg is pulled across a frictionless surface by a rope. The rope is at an angle of 30 degrees from horizontal as shown in Figure 1. The tension in the rope is 100 Newtons.
    1. What is the acceleration of the block in the x direction?
    2. Starting from rest, how far will the block go in 100 milliseconds?
  7. A racecar is going through a turn at a speed of 200 mi/hr (89.4 m/s). The centripetal acceleration is 2.50g (2.50 times the acceleration of gravity). What is the radius of the turn?
  8. A 10 kg block is suspended from the ceiling using two cables as shown in Figure 2. What is the tension in the cable on the right?
  9. The cart shown in Figure 3 rolls down the frictionless inclined rail starting from rest. How long does it take the cart to go one meter?
  10. A suitcase is pulled 50 m along a horizontal surface as shown in Figure 4. The person pulls the suitcase with a force of 50 N at an angle of 50o from the horizontal. Find the work done by the force in pulling the suitcase the distance of 50 m.
  11. If electricity costs 15¢ per kilowatt-hour, what does it cost to leave a 60-watt light bulb on continuously for 30 days?
  12. Jimmy McFearless is cruising along at 20 m/s when he runs out of gas as he approaches the hill shown below. The height of the hill, H, is 15 meters. Neglecting friction, can he coast up the hill and reach the gas station?

  13. Find the speed of a point on the equator due to the earth's rotation. Take the radius of the earth to be 6370 km.
  14. Find the force, F, exerted on the rope in the pulley system supporting the 500 Newton weight shown in Figure 6.
  15. A wheel 0.250 meters in radius turning at 120 rpm increases its speed to 660 rpm in 9.00 s. Find
    1. The angular acceleration,
    2. The tangential acceleration of a point on its rim.
    3. The centripetal acceleration of a point on its rim when the speed is 660 rpm.
  16. A 5.0 kg block of wood rests on a long tabletop. A 3.0 g bullet moving horizontally with a speed of 150 m/s is shot into the block and sticks in it. The block then slides 310 cm along the table and stops.
    1. Find the speed of the block just after impact.
    2. Find the friction force between block and table.
  17. One end of a meter stick is pinned to a table, so the stick can rotate freely in a plane parallel to the tabletop. Two forces, both parallel to the tabletop, are applied to the stick in such a way that the net torque is zero. One force has a magnitude of 3.0 N and is applied perpendicular to the length of the stick at the free end. The other force has a magnitude of 8.00 N and acts at a 30.0o angle with respect to the length of the stick as shown below.

    Where along the stick is the 8.00 N force applied? Express this distance with respect to the end that is pinned.

  18. A clay vase on a potter's wheel experiences an angular acceleration of 10.0 rad/s2 due the application of a 12.0 N*m torque. Find the total moment of inertia of the vase and the potter's wheel.
  19. An airplane flying horizontally at 125 m/s, 400 m above level ground drops a rescue package.
    1. How long does it take the package to reach the ground?
    2. What is the speed of the package when it reaches the ground?
  20. A 1.20 kHz wave with an amplitude of 10 is propagating in the positive x direction with a velocity of 343 m/s. Write a mathematical expression for this wave.