1. Topic 9
Simple Machines

2. A screwdriver is used to pry the lid off a can of paint
A screwdriver is used to pry the lid off a can of paint. What type of lever is the screwdriver in this instance?
1st Class Lever
2nd Class Lever
3rd Class Lever
It’s actually acting as an inclined plane. 10

3. Calculate the ideal mechanical advantage of a ramp that is 25 meters long and rises a total of 3.0 meters.
.12
3.0
8.3 25 75 10

4. Calculate the ideal mechanical advantage of a machine with a wheel that has a radius of 35 cm and an axle with a radius of 10 cm.
.29
1.7
3.5 28
350 10

5. Participant Scores 12
Jacob
Joey
Daniel
David
Nicole B.

6. A single pulley is used to hoist a safe with a mass of 45. 0 kg
A single pulley is used to hoist a safe with a mass of 45.0 kg. If the machine is 100% efficient, what effort force will be required to hoist the safe?
45.0 N
90.0 N
205 N
266 N
441 N 10

7. 1st Class 2nd Class 3rd Class
A snow shovel is an example of which type of lever? (Hint: The handle of the shovel is the fulcrum.)
1st Class
2nd Class
3rd Class 10

8. How long must an inclined plane be to push a 100 kg object to a height of 2.0 meters using a force of 200 N? Friction can be ignored.
2.0 m
9.8 m
50 m
100 m
200 m
400 m 10

9. A wheel and axle machine requires an effort force of 5
A wheel and axle machine requires an effort force of 5.0 N to lift a load with a mass of 5.1 kg. If the machine is ideal and has a wheel radius of 12 cm, what is the radius of the axle?
1.0 cm
1.2 cm
5.0 cm
10 cm
1.2 m
2.4 m 10

10. Participant Scores 28
Jacob
Joey
Daniel
David
Mackenzie

11. How much force would be required to lift a 200 kg object using a lever if the object is meters from the fulcrum and the force is applied 4.00 meters from the fulcrum?
20 N
25 N
196 N
245 N
1960 N
Answer Now 10

12. What force will be required to push a 500 N box to a height of 2
What force will be required to push a 500 N box to a height of 2.50 meters on a ramp that is 10.0 meters long and 85% efficient?
4.00 N
50.0 N
106
125 N
147 N 10

13. A pulley system is 85% efficient. If an effort force of 58
A pulley system is 85% efficient. If an effort force of 58.8 N is required to lift a 150 N load, how many strings are pulling up in the system? 1 2 3 4 5 10

14. Calculate the ideal mechanical advantage of a lever in which the load is half the distance from the fulcrum as the effort force.
0.50
1.00
1.50
2.00
2.50
Answer Now 10

15. Participant Scores 44
Jacob
Mackenzie 39
Nicole F.
Joey
Daniel

16. A ramp is 12 meters long and 3. 0 meters high
A ramp is 12 meters long and 3.0 meters high. It takes 145 N of force to push a 400 N crate up the ramp. Determine the efficiency of the ramp.
.36 %
.69 %
3.0 %
8.2 %
36 %
69 %
145 % 10

17. An object is placed 1. 75 meters from the fulcrum of a lever
An object is placed 1.75 meters from the fulcrum of a lever. The effort force is 0.50 meters from the fulcrum. What is the actual mechanical advantage if the lever is 95% efficient?
.271
.286
.301
3.33
3.50
3.68
Answer Now 10

18. A wheel and axle machine has a wheel radius of 15 cm and an axle radius of 6.5 cm. If an effort force of 49 N is required to lift a 10 kg object, calculate the efficiency of the machine.
20%
31%
69%
80%
87%
96%
Answer Now 10

19. Participant Scores 56
Jacob
Mackenzie 51
Nicole F.
Joey
Daniel

20. A certain ramp is 10 meters long and is 50% efficient
A certain ramp is 10 meters long and is 50% efficient. It requires 25 N of force to push a 50 N crate up the ramp. How tall is the ramp?
1.0 m
2.0 m
2.5 m
3.5 m
4.0 m
5.0 m 10

21. Which of the following are possibilities for the ideal mechanical advantage of a 2nd class lever? (select all that apply)
less than 1
equal to one
greater than one 10

22. Participant Scores Participant 1 Participant 2 Participant 3
Participant 1
Participant 2
Participant 3
Participant 4
Participant 5
Participant 6
Participant 7
Participant 8
Participant 9
Participant 10