Mechanical Comprehension Practice Set 1

  2. Select the best answer for each question. This question set has 16 practice questions, which is the number of Mechanical Comprehension questions you will see if you take the CAT-ASVAB.

  3. The work required to lift an object is the same as
    1. the change in potential energy of the object
    2. the weight of the object divided by gravity
    3. the force required to overcome friction
    4. half of the work required to put the object down
  4. A constant force of 2 N is applied to a mass of 6 kg that is initially at rest for 3 seconds. Assuming there is no friction or any other force applied to the mass, what is the velocity of the mass after 3 seconds?
    1. 0.5 m/s
    2. 1.0 m/s
    3. 6.0 m/s
    4. 12.0 m/s
  5. Approximately how much force is needed to lift the weight below?
    Image Missing
    1. 6 lbs
    2. 12 lbs
    3. 24 lbs
    4. 48 lbs
  6. If a ball is dropped from a height of 5 m, what will be its approximate speed when it hits the ground?
    1. cannot be determined because the mass is unknown.
    2. cannot be determined because the time it takes to reach the ground is unknown.
    3. 5 m/s
    4. 10 m/s
  7. Adam’s car is stuck in the mud, so he recruits some friends to help push it out. If they apply 2,000 N of force to push the car 5 m, how much work did they accomplish?
    1. 400 J
    2. 1,000 J
    3. 2,000 J
    4. 10,000 J
  8. A machine in an assembly plant lifts parts weighing 10 N each from the floor to a height of 2 m. If this machine must lift batches of 20 parts at a time in 2 seconds, what amount of power is required?
    1. 20 watts
    2. 100 watts
    3. 200 watts
    4. 400 watts
  9. A man who weighs 900 N wants to compress some loose soil in his garden, so he puts a thick plate that is m wide and m long on the ground and stands on the plate. Assuming that the plate distributes his weight evenly, how much pressure is applied to the soil?
    1. 900
    2. 1600
    3. 1800
    4. 2400
  10. Gear A has 15 teeth and gear B has 10. If gear A makes 14 revolutions, how many will gear B make?
    Image Missing
    1. 7
    2. 14
    3. 21
    4. 28
  11. Two wheels are secured to a common axle. If the larger wheel has a radius of m and the smaller wheel has a diameter of m, what is the mechanical advantage for a force applied to the larger wheel?
    1. 5 to 1
    2. 10 to 1
    3. 20 to 1
    4. 40 to 1
  12. A basic kitchen knife, like the one below, is based on which of the following simple machines?
    Image Missing
    1. wedge
    2. first-class lever
    3. pulley
    4. second-class lever
  13. In order for Person X pulling a rope to lift an object with a block and tackle at the same rate of speed as Person Y pulling a rope to lift an identical object with a simple pulley, Person X will have to pull the rope as Person Y.
    1. at the same rate
    2. faster
    3. slower
    4. at a rate based on the ratio of the diameters of the pulleys
  14. How much force is needed to apply 50 ft-lb of torque to a bolt using a 2 ft long wrench?
    1. 100 pounds
    2. 50 pounds
    3. 40 pounds
    4. 25 pounds
  15. If a 10 N force applied to an object produces an acceleration of 10 m/s2, assuming friction is NOT negligible, what could the mass of the object have been?
    1. less than 1 kg
    2. equal to 1 kg
    3. between 10 kg and 1 kg
    4. greater than 10 kg
  16. The force of friction between two surfaces moving past each other DOES NOT depend on
    1. the normal force
    2. the nature of the surfaces in contact with each other
    3. the area of the surfaces in contact with each other
    4. the speed at which the surfaces are moving past each other
  17. The gravitational acceleration on Earth, g, is 9.8 m/s2. The gravitational acceleration on a neighboring planet, Xendor, is 3 times as much. What is the approximate weight of a 100 kg person on Xendor? (Hint: you can approximate the gravitational acceleration on Earth as 10 m/s2 to make calculations easier.)
    1. 100 N
    2. 300 N
    3. 1,000 N
    4. 3,000 N
  18. Assuming no friction, if 80 J of work was done to move an object 2 m, what was the net force that was applied?
    1. 4 N
    2. 16 N
    3. 40 N
    4. 160 N

Mechanical Comprehension Practice Set 2

  1. Select the best answer for each question. This question set has 16 practice questions, which is the number of Mechanical Comprehension questions you will see if you take the CAT-ASVAB.

  2. A man pushes against an object at rest, but fails to get it moving. Which of the following must be true about the relationship between the applied force and the force of friction?

    1. The applied force is less than the force of static friction.
    2. The applied force is equal to the force of kinetic friction.
    3. The applied force is equal to the force of static friction.
    4. The applied force is greater than the force of static friction.

  3. A ball with a mass of 10 kg starts rolling down a hill 20 m high. What is its approximate velocity when it hits the bottom, ignoring resistance?

    1. 10 m/s
    2. 15 m/s
    3. 20 m/s
    4. 40 m/s

  4. A 500 g block made from a uniform material is suspended from the ceiling by two equal length ropes equidistant from the center of the block, as depicted in the figure below. Which of the following best approximates the tension in rope 1 (T1)?

    image
    1. 2.5 N
    2. 5.0 N
    3. 50 N
    4. 250 N

  5. A hydraulic lift is set up as depicted below. Which of the following must be true? [Insert 'ASVAB_MC_20_graphic'] 

    1. The work done by Force 2 is greater than the work done by Force 1, since Force 2 is applied over a longer distance.
    2. To do the same amount of work, Force 2 must be smaller than Force 1, but applied over a larger distance.
    3. Force 1 must be greater than Force 2, because more work must be done by Force 1.

    4. The pressure in the left side of the lift must be greater than the pressure in the right side of the lift, since Force 1 is larger.

  6. Two weights, one with a mass of 10 kg and another with a mass of 20 kg, are placed on opposite ends of a 9 m rod. To achieve rotational equilibrium, what distance from the 10 kg weight must the fulcrum be placed?

    image
    1. 3.0 m
    2. 4.5 m
    3. 6.0 m
    4. 8.0 m

  7. What is the kinetic energy of a 98 N object moving at 100 m/s?

    1. 10,000 J
    2. 50,000 J
    3. 100,000 J
    4. 500,000 J

  8. A net force of 30 N is applied to a 1,000 kg car over 150 m. If the car starts from rest, what is its final velocity?

    1. 1 m/s
    2. 3 m/s
    3. 10 m/s
    4. 30 m/s

  9. A man pushes a 50 kg block a distance of 10 meters in 20 seconds with a force of 100 N. How much power did he exert?

    1. 25 W
    2. 50 W
    3. 100 W
    4. 200 W

  10. Based on the diagram below, approximately what minimum force must be applied to the rope to lift the object?

    Image Missing
    1. 25 N
    2. 50 N
    3. 100 N
    4. 250 N

  11. Snowshoes are used to reduce the pressure exerted by the feet when walking on top of deep snow. A 150 lb woman puts on two rectangular snowshoes with dimensions 10 inches by 15 inches each. What pressure does the woman exert on the snow while both shoes are equally bearing her full weight?

    1. 0.5 psi
    2. 1.0 psi
    3. 5.0 psi
    4. 10.0 psi

  12. A 40 kg block is sitting on a table and it is also pushed down by a 100 N force. What is the magnitude of the normal force provided by the table if the object remains at rest? (Use 10 m/s2 for gravity.)

    1. 140 N
    2. 300 N
    3. 400 N
    4. 500 N

  13. A ball with a mass of 5 kg is thrown from a height of 10 meters at an angle of 30° above the horizontal with an initial velocity of 10 m/s. Consider any resistance to be negligible. What is the approximate total kinetic energy when the ball hits the ground?

    1. 250 J
    2. 300 J
    3. 500 J
    4. 750 J

  14. Which of the answer choices best describes the topics that are included in the area of physics known as “mechanics?”

    1. the proper use of tools and measuring devices
    2. machines that transmit or use energy
    3. the laws of motion, energy, and forces
    4. the laws of trajectories, energy, and forces

  15. Once sufficient force is applied to a stationary object to overcome static friction, if the same force is maintained, the object will accelerate. This is true because __________.

    1. the force that is applied accumulates
    2. the coefficient of kinetic friction is greater than the coefficient of static friction
    3. the coefficient of static friction is greater than the coefficient of kinetic friction
    4. the object's momentum is cumulative

  16. Playground seesaws are constructed in the same way as first-class levers. A boy wants to play on the seesaw with his little brother. The big brother weighs 100 pounds; the little brother weighs 75 pounds and sits 8 feet from the center of the seesaw. In order for the two brothers to be balanced, how far from the center of the seesaw should the big brother sit?

    1. 6.0 feet
    2. 8.0 feet
    3. 10.0 feet
    4. 12.5 feet

  17. A hydraulic lift has a 2 cm diameter piston that exerts a downward force of 20 N on the incompressible fluid in a closed system. If the piston that is at the other end has a diameter of 20 cm, how much upward force can it exert?

    1. 20 N
    2. 200 N
    3. 1,000 N
    4. 2,000 N