31 Jan C. your friend’s home.

Question 1

1. If a man is standing more than one focal length away from the focal point of a concave mirror, how will his image form in the mirror?

A. Right side up

B. Enlarged

C. No image

D. Upside down

Question 2

2. Which of the following displays a noncontact force?

A. Hitting a golf ball onto a fairway

B. Opening a door

C. Two magnets pulling toward one another

D. Typing on a keyboard

Question 3

3. What’s the net force acting on an 18-kg object if an acceleration of 3.0 m/s2 is produced?

A. 6 N

B. 54 N

C. 36 N

D. 12 N

Question 4

4. If a 3-kg object has a momentum of 33 kg·m/s, what’s its velocity?

A. 36 m/s

B. 99 m/s

C. 9.1 m/s

D. 11 m/s

Question 5

5. If one ball with a momentum of 50 kg·m/s hits a ball at rest and no other forces are acting on either ball, what’s the total momentum of both balls after the collision?

A. 25 kg·m/s

B. 0 kg·m/s

C. 50 kg·m/s

D. 100 kg·m/s

Question 6

6. Calculate the percent error if the experimental value of the density of copper is 21.2 g/cm3 and the accepted value is 22.1 g/cm3.

A. 4.25%

B. 4.02%

C. 4.07%

D. 4.19%

Question 7

7. What’s the momentum of a 3.5-kg boulder rolling downhill at 5 m/s?

A. 17.5 km·m/s

B. 70 kg·m/s

C. 8.5 kg·m/s

D. 14.3 kg·m/s

Question 8

8. Four forces are being applied to move an object to the left. Force 1 is pushing to the right at 200 N. Force 2 is pushing to the left at 500 N. Force 3 is pushing to the right at 100 N. Force 4 is pushing to the left at 50 N. What’s the net force acting on this object?

A. 250 N

B. 650 N

C. 850 N

D. 0 N

Question 9

9. Which of the following would increase friction?

A. Soap

B. Water

C. Sand

D. Motor oil

Question 10

10. What’s the speed of a sound wave through water at 25° Celsius?

A. 1,000 m/s

B. 1,250 m/s

C. 1,500 m/s

D. 750 m/s

Question 11

11. When viewing an object, we see its color according to the wavelength of light that the object

A. reflects.

B. transmits.

C. contains.

D. absorbs.

Question 12

12. Which of the following simple machines is not properly identified?

A. Screw: wheel and axle

B. Ramp: inclined plane

C. Scissors: lever

D. Pizza cutter: wedge

Question 13

13. Which one of the following SI base units is not matched to the correct unit of measurement?

A. Length: km

B. Mass: kg

C. Temperature: K

D. Time: s

Question 14

14. If an object is thrown 60 m into the air and it takes the object 6 s to get there, what’s the average speed of the object?

A. 100 m/s

B. 20 m/s

C. 360 m/s

D. 10 m/s

Question 15

15. If a system requires 150 J of input work and produces 123 J of output work, what’s its efficiency?

A. 72%

B. 92%

C. 82%

D. 122%

Question 16

16. You’re watching television and an infomercial comes on for a new stain removal product called “Mr. Fantastic.” This product claims to remove any stain from any material, no matter how old it is. You’ve just finished reading an extensive article about why some stains can’t be removed. By comparing these two pieces of information, you’re utilizing which of the following?

A. Logic

B. Critical thinking

C. Observation

D. Prediction

Question 17

17. In a controlled experiment, the factor tested is called the

A. control.

B. constant.

C. dependent variable.

D. independent variable.

Question 18

18. Which of the following best explains velocity?

A. Only the change of direction of an object in motion

B. The speed of an object in motion

C. The direction of an object in motion

D. The speed and direction of an object in motion

Question 19

19. If you’re giving a friend directions from your home, to your school, and then to the park, the original reference point would be

A. your school.

B. your home.

C. your friend’s home.

D. the park.

Question 20

20. In scientific notation, the number 39,940,000,000 becomes

A. 3.994 × 1010.

B. 39.94 × 109.

C. 3994 × 107.

D. 3.994 × 10–10.