MC

8th Grade Integrated Science

Standard:  04

Objective:  03.  Investigate the application of forces that act on objects, and the resulting

                         motion.

ILO:

 

 

Which one of the following simple machines is a third class lever?

a. Bumper jack

b. Crowbar

c. Fishing pole

d. Scissors

e. Wheel barrow

 

Correct Answer: c

 

MC

8th Grade Integrated Science

Standard:  04

Objective:  03.  Investigate the application of forces that act on objects, and the resulting

                         motion.

ILO:

 

 

A simple machine is used to lift a weight. What happens to the amount of force that must be exerted compared to doing the work without a machine?

a. it increases

b. it decreases

c. it stays the same

d. it can't be predicted

 

Correct Answer: b

 

MC

8th Grade Integrated Science

Standard:  04

Objective:  03.  Investigate the application of forces that act on objects, and the resulting

                         motion.

ILO:

 

 

A simple machine is used to lift a weight. What happens to the amount of distance the force is exerted over if a machine is used?

a. it increases

b. it decreases

c. it stays the same

d. it can't be predicted

 

Correct Answer: a

 

MC

8th Grade Integrated Science

Standard:  04

Objective:  03.  Investigate the application of forces that act on objects, and the resulting

                         motion.

ILO:

 

 

A simple machine is used to lift a weight.  What happens to the amount of work that must be done compared to doing the work without a machine?

a.  It increases

b.  It decreases

c.  It stays the same

d.  It depends on which simple machine is used

 

Correct Answer:  c

 

MC

8th Grade Integrated Science

Standard:  04

Objective:  03.  Investigate the application of forces that act on objects, and the resulting

                         motion.

ILO:

 

 

Use this picture to answer the following question:

 

 

If the blades of the scissors were lengthened, what would happen to the amount of force exerted at their tip?

a.  It would not change

b.  It would become greater

c.  It would become less

d.  It would be easier to cut tough materials

 

Correct Answer: c

 

MC

8th Grade Integrated Science

Standard:  04

Objective:  03.  Investigate the application of forces that act on objects, and the resulting

                         motion.

ILO:

 

 

 

What simple machines are found in the wheelbarrow?

            a.  inclined plane, lever

            b.  lever, pulley

            c.  pulley, inclined plane

            d.  wheel, lever

 

Correct Answer:  d

 

MC

8th Grade Integrated Science

Standard:  04

Objective:  03.  Investigate the application of forces that act on objects, and the resulting

                         motion.

ILO:

 

 

Brakes in cars work by pressing pads together within the car's wheel assembly. This resistance to the motion of the car results from:

a.  Fluid friction

b.  Gravity

c.  Rolling friction

d.  Sliding friction

 

Correct Answer:  d

 

MC

8th Grade Integrated Science

Standard:  04

Objective:  03.  Investigate the application of forces that act on objects, and the resulting

                         motion.

ILO:

 

 

Which of the following is an example of sliding friction?

a. A car going down the road.

b. A person sanding a board.

c. A ball being pushed across a table.

d. A boy climbing a greased pole.

e. A boulder being moved on rolling logs.

 

Correct Answer: b

 

MC

8th Grade Integrated Science

Standard:  04

Objective:  03.  Investigate the application of forces that act on objects, and the resulting

                          motion.

ILO:

 

 

Henry built a machine that consisted mostly of ropes and pulleys.  The machine was designed to lift his dirty laundry from his basement bedroom up and over to the laundry room.   He placed a 20 pound basket of laundry on the base of the machine, pulled on the ñupî rope and up the laundry went!  The he pulled on the ñoverî rope and it made it to the laundry room.  Henry was very happy when he finally got it to work.  HenryÍs machine

            a.  made his life better because he never had to be seen carrying dirty laundry again.

b.  made his life better because now he was able to put less effort into getting his dirty laundry to the laundry room.

c.  made his life better because less work was done on the clothes to get them to the laundry room.

d.  made his life worse because now other people wanted to hire him to make them a laundry machine.

 

Correct Answer:  b

 

MC

8th Grade Integrated Science

Standard:  04

Objective:  03.  Investigate the application of forces that act on objects, and the resulting

                          motion.

ILO:

 

 

A simple machine is used to lift a weight. What happens to the amount of force that must be exerted if the work is done without a machine?

a. it increases

b. it decreases

c. it stays the same

d. it can't be predicted

 

Correct Answer: a

 

MC

8th Grade Integrated Science

Standard:  04

Objective:  03.  Investigate the application of forces that act on objects, and the resulting

                          motion.

ILO:

 

 

A car changing speed from 10 mph to 50 mph would be an example of:

a.  Acceleration

b.  Constant speed

c.  Deceleration

d.  Velocity

 

Correct Answer:  a

 

MC

8th Grade Integrated Science

Standard:  04

Objective:  03.  Investigate the application of forces that act on objects, and the resulting

                         motion.

ILO:

 

 

A rope is tied to a 400 N railroad tie and the tie is dragged by pulling up, straight, and down. Which of the following statements is true?

a.  Since all the forces are the same the railroad tie will move the same.

b.  The force pulling straight creates the most opposing friction.

c.  The force pulling up creates the least opposing friction

d.  The force pulling down moves the tie the most because it is closest to the ground.

 

Correct Answer:  c

 

MC

8th Grade Integrated Science

Standard:  04

Objective:  03.  Investigate the application of forces that act on objects, and the resulting

                          motion.

ILO:

 

 

Susie was performing a lab in her science class.  She was using a spring scale and dragging a 500 gram mass across a table past an accelerometer.  She was told to fill out the following chart as she did the experiment.

 

Force

Mass

Acceleration

1N

 

.5 kg

 

5N

 

.5 kg

 

10N

 

.5 kg

 

20N

 

.5 kg

 

 

She learned Newton's 2nd law in the previous class and decided to fill in her chart using his law rather than the readings the accelerometer gave her.

 

Acceleration                                        Acceleration

She reported:               2 m/s2                         Instead of:       1.4 m/s2

10 m/s2                                               7.2 m/s2

20 m/s2                                               14.1 m/s2

40 m/22                                               27.3 m/s2

(Calculation)                                       (Accelerometer reading)

 

a.  Susie should get a good grade because she remembered what she learned from the previous day.

b.  Susie should get a good grade because she wrote in more accurate results using one of Newton's laws.

c.  Susie should get a good grade because she really did what the teacher wanted.

d.  Susie should get a bad grade because she didn't report her honest results and let her observations be thrown out because of previous knowledge.

e.  Should get a bad grade because she used Newton's 2nd law when she should have been using his 3rd law.

 

Correct Answer:  d

 

 

I

8th Grade Integrated Science

Standard:  04

Objective:  03.  Investigate the application of forces that act on objects, and the resulting

                         motion.

ILO:

 

 

 

1.  Calculate the mechanical advantage of the lever drawn above.

            a.  1.5

            b.  2

            c.  2.5

            d.  3

 

2.  How could you increase the mechanical advantage of this lever?

            a.  make the weight lighter

            b.  make the weight heavier

            c.  move the fulcrum closer to the weight

            d.  move the fulcrum farther from the weight

 

Correct Answers: 

            1.  b

            2.  c

 

I

8th Grade Integrated Science

Standard:  04

Objective:  03.  Investigate the application of forces that act on objects, and the resulting

                         motion.

ILO:

 

 

 

1.  What is the mechanical advantage of this inclined plane drawn above?

            a.  1.5

            b.  2

            c.  2.5

            d.  3

 

2.  How could the mechanical advantage of this inclined plane be increased?

            a.  make the height taller

            b.  increase the weight

            c.  decrease the weight

            d.  make the plane longer

 

Correct Answers:

            1.  d

            2.  d

 

 

I

8th Grade Integrated Science

Standard:  04

Objective:  03.  Investigate the application of forces that act on objects, and the resulting

                         motion.

ILO:

 

 

 

1.  What is the mechanical advantage of the pulley drawn above?

            a.  1

            b.  2

            c.  3

            d.  4

 

2.  How can you increase the mechanical advantage of this pulley system?

            a.  use a longer rope

            b.  use more pulleys

            c.  add more weight

            d.  reduce the weight

 

Correct Answers:

            1.  c

            2.  b

 

 

 

I

8th Grade Integrated Science

Standard:  04

Objective:  03.  Investigate the application of forces that act on objects, and the resulting

                         motion.

ILO:

 

 

Use this diagram to answer the next questions:

 

1. What is the name of the simple machine shown in B, C, and D?

a. inclined plane

b. lever

c. pulley

d. wheel

 

2. Which system would change the direction of the force needed to lift the weight?

a. A

b. B

c. B and C

d. C and D

 

3. Which would reduce the amount of force needed to lift the weight?

a. A