need help with science questions best answer 10 points?

Tom Asked: need help with science questions best answer 10 points?

1. What is the unit used for force? (Points : 3)
MA
Newton
Joule
Watt

2. Force and distance are required to calculate which of the following? (Points : 3)
Power
Time
Mechanical Advantage
Work

3. Jen pushed a box for a distance of 80m with 20 N of force. How much work did she do? (Points : 3)
1,600 J
60 J
.25 J
150 J

4. Mike is complaining that he did 150 J of work when moving a couch that has a mass of 30 kg a distance of 15 m. How much force did he use to move the couch? (Points : 3)
10 N
5 N
120 N
135 N

5. Which of the following is the equation used to calculate power? (Points : 3)
P = W x t
P = t x d
P = W/d
P = W/t

6. What can you calculate using the equation: P=W/t? (Points : 3)
distance
mass
power
time

7. Sam did 480 J of work when moving a bag with a mass of 38 kg. He did the work in 4 minutes. What was the power output? (Points : 3)
442 W
20 W
120 W
2 W

8. Lee has been moving a crate that has a mass of 125 kg and required 120 J of work to move. The crate was moved a distance of 20 meters in 30 seconds. What was the power output? (Points : 3)
6.25 W
4.16 W
6 W
4 W

9. How many classes of levers are there? (Points : 3)
2
3
1
10

10. Which of the following are modified inclined planes? (Points : 3)
pulley and wedge
lever and screw
gear and wedge
wedge and screw

11. Which of the following describes the mechanical advantage of a machine? (Points : 3)
the number of times that a machine multiplies the effort force
the number of times a machine multiplies the resistance force
the number of times a machine reduces the resistance force
the number of times a machine reduces the effort force

12. Which of the following pieces of information are needed to calculate the mechanical advantage of an inclined plane? (Points : 3)
the effort distance and the resistance force
the resistance force and height
the amount of effort needed to perform the work
the effort distance and the resistance distance

13. Which of the following is an example of a lever? (Points : 3)
knife
ramp
pencil sharpener
wheelbarrow

14. Which of the following contains a wheel and axle? (Points : 3)
stapler
bicycle
screw
computer

15. When less force is used but the amount of work done remains the same, how does distance change? (Points : 3)
Distance stays the same.
Distance is increased.
Distance is decreased.
Distance is dependent on the mass of the object.

16. Which of the following describes what happens to effort force when a car jack increases the distance over which the force is exerted? (Points : 3)
Force will be decreased.
Force will be increased.
Force will be unchanged.
Force will depend on the mass of the object.

17. Which of the following describes a machine that is made up of a lever and a wedge? (Points : 3)
simple machine
compound machine
pulley
efficiency

18. Which of the following is a compound machine? (Points : 3)
pry bar
water faucet handle
sliding door
toothbrush.

19. Which of the following explains why gears are used in a bicycle? (Points : 3)
increases effort force
increases resistance force
decreases effort force
decreases resistance force

20. Which of the following is contained in a bicycle? (Points : 3)
gears and inclined plane
inclined planes and screw
wheel and axle and screw
wheel and axle and inclined plane