Mechanical Comprehension - Fundamentals of Mechanics

When torque increases, speed _________.

Decreases.

Tension can best be called _________.

A force.

Which material is best suited for use as a boat anchor?

Metal.

How many kilograms is a cow on a trailer if 1200 newtons of force are acting on it?

122 kg.

In terms of force, what makes hydraulic jacks so useful?

The liquid does not compress very much.

Which of the following describes the relationship between kinetic energy, mass, and velocity?

2KE = mv²

Which term below best describes the opposite of an increase in speed?

Deceleration.

Energy is _________.

The capacity to do work.

Which of the following is an example of kinetic energy?

Leaves blowing.

A farmer is attempting to pull a log with a line of rope attached to a tractor. Where should she watch for breakage on the rope?

Nearest to the tractor.

Three beams are 10 feet long each and all of the same size. One is made of wood, another of steel, and the third of concrete. If identical loads are applied to these three beams, which of the following will happen?

The steel beam will deflect less than the wood beam.

Which of the following is NOT a unit of power?

Newton.

Which of the following is the basis for Pascal’s Law?

The amplification of force in a hydraulic system.

What is a vector quantity?

Gravity.

Which of the following statements is true for water flowing from a 4 inch pipe to a smaller 2 inch pipe?

The same amount of water passes through both the 4 inch pipe and the 2 inch pipe.

What is a component of potential energy?

Gravity’s relationship to mass.

Which of the following situations requires overcoming the least amount of kinetic friction?

Pushing an empty refrigerator box down an icy path.

15 J of work was expended moving an 18 kg block. At what velocity did the block move?

1.3 m/s.

Power is the _________.

Rate of work.

Which principle of mechanical motion is used in the design of a roller coaster?

All of the answers.

You’re using a 6-inch wrench to release the wheel nuts as you rotate your tires. If you’re applying 40 pounds of force, how much torque is on the wheel nut?

20 ft-lb

Work occurs when _________.

In the figure below, what is TRUE about supports A and B?

Support B carries more weight.

A fish tank at an aquarium contains several cubic feet of water (1 cubic foot of water = 62.5 pounds). If the fish tank is 6 feet deep, 12 feet wide, and 13 feet long, what’s the approximate pressure at the bottom of the tank in pounds per square inch?

2.5

A valve is used to perform which of the following functions?

Control the flow of a liquid.

Torque involves a perpendicular force applied to a lever arm that moves around a center of rotation. Increasing the length of the lever arm will do which of the following?

Increase torque.

A block of steel has a density of 0.29 pounds per cubic inch. If the block has dimensions of 1 inch by 1 inch by 3 inches, what is its weight?

0.87 pounds.

If a person weighing 60 kg sits on one end of a teeter-totter, the distance between the person and the fulcrum is 3 meters. How much weight is needed on the other end to balance the teeter-totter if the distance between the weight and the fulcrum is 4 meters?

45kg.

Weight is the _________.

Force exerted on an object due to gravity.

What would happen to a balloon full of air if you moved it from above a water surface to ten feet below the water surface?

The volume of the balloon would decrease.

In the diagram, the spring is very stiff and can be stretched 1 inch by a pulling force of 100 pounds. How much force must be applied to the block in order to move the box 3.5 inches to the left?

350 pounds.

What is the measure of “work” in physics?

Joule.

The measure of the quantity of matter in an object is its _________.

Mass.

A concrete beam has a maximum strength of 3,000 psi (pounds per square inch). In an experiment, a 500-pound weight is placed in the center of the beam, and the stress in the beam is measured to be 1,000 psi. If the stresses in the beam continue to increase at the same rate with added weight, how much additional weight can be added to the same location on the beam before the beam breaks?

1,000 pounds.

A 6 kg bowling ball rolled at 2 m/s expends how much work?

12 J

Which of the following measures the force's ability to cause an object to rotate?

Torque.

One horsepower is equivalent to _________.

746 watts.

A 180-pound person dives off of a 30-foot cliff. What is his velocity as he enters the water?

13.4 m/s.

The center of gravity of a baseball bat would be best described as _________.

Near the fat end.

What mechanical motion principle do the brakes in a car or on a bicycle use?

Friction.

An 80-lb child is sitting on one end of a seesaw. If another 80-lb child jumps from a high platform onto the other end of the seesaw, what will happen?

The first child will be lifted into the air, but remain seated.

If a man uses 200 N of force over a distance of 50 meters, how many joules of work are performed?

10,000

Which of the following would feel hottest at one end if the other end were placed over a fire?

A metal skewer.

The diagram below represents a load sliding down an incline. Which of the forces (A,B,C, or D) represent friction?

D

When a football is thrown upwards in the air, what causes it to arc back towards the ground?

Gravity.

Which of the following will happen when a mass of air contracts?

The air gets colder.

Water flows into a container at a rate of 140 gallons per minute. The container has a small opening at the bottom that drains water at a rate of 1 gallon per second. How long will it take to fill the container to 240 gallons?

3 minutes.

What is the mass of an object if it has a weight of 98 N?

10 kg.

According to Boyle's Law, what happens to the volume of a gas if its pressure is increased while keeping the temperature constant?

The volume decreases.

What is the relationship between force of friction and normal force?

They are directly proportional.

What is the coefficient of friction if the force of friction is 30 N and the normal force is 50 N?

0.6

What is the relationship between gravitational potential energy and height?

They are directly proportional.

Which statement best describes Newton's Second Law of Motion?

Acceleration is directly proportional to net force and inversely proportional to mass.

What is the work-energy theorem in physics?

The work done on an object is equal to the change in its kinetic energy.

What is the formula for work in physics?

W = Fd cos(theta)

What is the work done on an object when a force of 20 N moves it a distance of 5 meters in the direction of the force?

100 J

What is the formula to calculate force according to Newton's Second Law of Motion?

F = ma

What is the formula for power in physics?

P = W/t