Expert Answers


1. Which of the following would increase friction?

A. Soap
B. Sand
C. Water
D. Motor oil

2. In scientific notation, the number 39,940,000,000 becomes
A. 39.94 × 109
B. 3.994 × 1010
C. 3994 × 107
D. 3.994 × 10–10

3. If an object moves 40 m north, 40 m west, 40 m south, and 40 m east, what’s the total displacement?
A. 0 m
B. 160 m
C. 80 m
D. 40 m

4. Two objects are 5 kg and 10 kg respectively, and they’re 10 m apart. If the distance between them is increased to 20 m, what happens to the gravitational force?
A. It decreases.
B. It is doubled.
C. It doesn’t change.
D. It increases slightly.

5. Dave is riding on a straight path. After 5 s, his speed is 3.0 m/s. After 7 s, his speed is 5.0 m/s. After 10s, his speed is 7.0 m/s. What was his acceleration from 5 s to 10 s?
A. 2.0 m/s2
B. 0.8 m/s2
C. 1.0 m/s2
D. 0.67 m/s2

6. In a controlled experiment, the factor tested is called the
A. constant.
B. dependent variable.
C. control.
D. independent variable.

7. Light has what range of wavelength?
A. 400 nm to 10 nm
B. 10 nm to 0.01 nm
C. 0.3 nm to 0.001 nm
D. 700 nm to 400 nm

8. 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. 20 m/s
B. 10 m/s
C. 100 m/s
D. 360 m/s

9. Which of the following statements is true about data recording and evidence gathering?
A. Qualitative data uses words, while quantitative data uses numbers.
B. Qualitative data uses numbers, while quantitative data uses words.
C. Quantitative data is opinion based.
D. Qualitative data uses words and numbers.

10. 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. 4.07%
C. 4.19%
D. 4.02%

11. Which of the following is not purely potential energy?
A. Gravitational energy
B. Nuclear energy
C. Thermal energy
D. Chemical energy

12. 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. 100 kg•m/s
B. 0 kg•m/s
C. 25 kg•m/s
D. 50 kg•m/s

13. If John travels 2,387 miles in 2 days, what’s his average speed per hour?
A. 49.7 mph
B. 1,193.5 mph
C. 73.7 mph
D. 99.5 mph

14. Which one of the following SI base units is not matched to the correct unit of measurement?
A. Length: km
B. Temperature: K
C. Time: s
D. Mass: kg

15. In the human eye, where is the actual image formed before being transmitted to the brain?

A. Cornea
B. Optic nerve
C. Pupil
D. Retina

16. Energy is _______ when it’s moved from one object to another.
A. conducted
B. transferred
C. lost
D. created

17. Which of the following is not part of testing a hypothesis?
A. Modeling
B. Reasoning
C. Collecting data
D. Gathering evidence

18. When viewing an object, we see its color according to the wavelength of light that the object
A. reflects.
B. transmits.
C. absorbs.
D. contains.

19. What’s the momentum of a 3.5-kg boulder rolling downhill at 5 m/s?
A. 14.3 kg•m/s
B. 17.5 km•m/s
C. 8.5 kg•m/s
D. 70 kg•m/s

20. What’s the speed of a sound wave through water at 25° Celsius?
A. 750 m/s
B. 1,000 m/s
C. 1,250 m/s
D. 1,500 m/s