Chapter 13 Science Test

a lever or pulley connected to a shaft

wheel and axle

an example of a second-class lever

wheelbarrow

A pulley with a mechanical advantage of 5.00 is used to lift a bucket weighing 285 N. How much force must be used to lift the bucket? a. 57.0 N b. 280 N c. 285 N d. 1,425 N

a. 57.0 N

Mechanical energy can change to nonmechanical energy as a result of a. air resistance b. heat c. radiation d. None of the above

a. air resistance

Lifting a car using a car jack is easier because it requires a. less force b. less work. c. less time. d. None of the above

a. less force

energy that lies at the level of atoms and that does not affect motion on a large scale

nonmechanical energy

_____ is defined as the rate at which work is done a. Power b. Joule c. Speed d. Mechanical advantage

a. Power

Which of the following is an example of a third-class lever? a. hand-held boat paddle b. a screw c. a nutcracker d. a crow bar

a. a hand-held boat paddle

A machine is a device that a. can multiply and change the direction of an input force b. decreases the amount of work done by a given force c. requires less work to do a given task d. increases energy

a. can multiply and change the direction of an input force

An inclined plane a. changes both the magnitude and the direction of the force b. changes the magnitude of the force only c. changes the direction of the force only d. decreases the amount of work done

a. canges both the magnitude and the direction of the foce

At the top of its arc, a thrown ball has _____ potential energy. a. maximum b. minimum c. zero d. average

a. maximum

When a pitcher throws a softball to a catcher, the vibration of the atoms that make up the softball is ____ energy, while the motion of the ball toward the catcher is ____ energy. a. nonmechanical, mechanical b. potential, nonmechanical c. electrical, thermal d. mechanical, chemical

a. nonmechanical, mechanical

A system that receives energy from external sources is called a. open b. closed c. compound d. efficient

a. open

Which of the following is an example of mechanical energy? a. potential energy b. nuclear energy c. light energy d. chemical energy

a. potential energy

Which of the following is an example of a compound machine? a. scissors b. ax blade c. wheel and axle d. screw

a. scissors

Calculate the mechanical advantage of a wrench that allows you to move a bolt 0.01 m by moving the handle 0.50 m. a. 0.05 b. 0.50 c. 5.0 d. 50

d. 50

An 84% efficient single pulley is used to lift a 230 kg piano 3.5 m. How much work must be input? a. 676 J b. 9.6 x 10^2 J c. 6.6 x 10^3 J d. 9.4 x 10^3 J

d. 9.4 x 10^3 J

Gravitational potential energy depends on a. the height of the object b. the mass of the object c. the acceleration due to gravity d. All of the above

d. All of the above

What are the units of power? a. joules per second b. horsepower c. watts d. All of the above

d. All of the above

What are the units of work? a. N x m b. kg x m^2/s^2 c. J d. Al of the above

d. All of the above

A pair of tweezers is a. a first-class lever b. a kind of wedge c. a compound machine made of two second-class levers. d. a compound machine made of two third-class levers.

d. a compound machine made of two third-class levers

The kind of energy associated with atomic bonds is a. kinetic energy b. nuclear energy c. light energy d. chemical energy

d. chemical energy

_____ is a measure of the ability to do work a. photosynthesis b. power c. respiration d. energy

d. energy

Which of the following statements is not true? a. THe energy of an open system can increase b. the energy of a closed system is constant c. energy cannot be created or destroyed d. if the kinetic energy of an object decreases, the nonmechanical energy will decrease

d. if the kinetic energy of an object decreases, the nonmechanical energy will decrease

A ramp is a simple inclined plane that allows one to apply an input force _____ the output force a. perpendicular to b. equal to c. greater than d. less than

d. less than

A ramp is a ______ that decreases the force required to move an object while increasing the distance the object travels a. force b. load c. newton d. machine

d. machine

The primary source of the sun's energy is a. nuclear fission b. chemical energy c. potential energy d. nuclear fusion

d. nuclear fusion

As a dropped penny falls toward the ground, ____ energy is converted to ____ energy. a. thermal, potential b. kinetic, vibrational c. kinetic, heat d. potential, kinetic

d. potential, kinetic

the energy of an object due to its position, shape or condition

potential energy

an inclined plane wrapped around a cylinder

screw

A first-class lever can have an input force greater than the output force

True

A second-class lever always has an input force that is less than the output force

True

Because of friction, using machine increases the amount of energy that is needed to do work

True

Increasing the angle a ramp makes with the horizontal decreases the mechanical advantage

True

What is the mechanical advantage of a single, fixed pulley? a. 0.5 b. 1 c. 2 d. 4

b. 1

What is the work output by a 92% efficient wheel and axle when 75 J of work is input? a. 67 J b. 69 J c. 75 J d. 81.5 J

b. 69 J

_____ is the ratio of useful work output to work input a. Potential energy b. Efficiency c. Kinetic energy d. Power

b. Efficiency

Which of the following is not a simple machine? a. a wheel and axle b. a pair of scissors c. a lever d. a screw

b. a pair of scissors

Which of the following is not in the inclined plane family? a. a ramp b. a wheel and axle c. a screw d. a wedge

b. a wheel and axle

The law of conservation of energy states that energy a. is created from motion b. cannot be created or destroyed c. is always equal and opposite d. can only be converted into heat

b. cannot be created or destroyed

A wheelbarrow is an example of a. first-class lever b. second-class lever c. third-class lever d. fourth-class lever

b. second-class lever

Levers are divided into ____ classes based on the location of the fulcrum and of the input and output forces a. two b. three c. four d. five

b. three

The transfer of energy to a body by the application of a force that causes the body to move in the direction of the force is called a. power b. work c. distance d. mechanical advantage

b. work

multiple pulleys put together in a single unit

block and tackle

What is the mechanical advantage of a ramp 2.0 m long and 0.50 m tall? a. 1.0 b. 2.5 c. 4.0 d. None of the above

c. 4.0

How efficient is a machine that uses 130 J to lift a 50.0 N load 2.0m? a. 19% b. 52% c. 77% d. 87%

c. 77%

A wedge is a modified a. wheel and axle b. pulley c. inclined plane d. lever

c. inclined plane

What are the two families of simple machines? a. wedge and compound b. first class and second class c. inclined plane and lever d. pulley and screw

c. inclined plane and lever

A dropped racquetball will not return t its original position because a. potential energy is inefficient. b. the mechanical energy is stored up for later bounces. c. some of the mechanical energy is converted to nonmechanical energy d. energy is not conserved

c. some of the mechanical energy is converted to nonmechanical energy

the energy due to motion

kinetic energy

the sum of an object's kinetic and potential energies

mechanical energy