Answer the Questions:

1. You are watching an old, rickety bridge being detonated, making way for a newer, safer, design.

You see the bridge detonate first and you hear the sound of the explosion four seconds later. How far away from the bridge were you standing? Assume the speed of sound is 345 m/s and constant (that is, v_f= v_i).

a. 690 m

b. 86.3 m

c. 1500 m

d. 1380 m

2. You travel 1000 m in 25 seconds, accelerating the whole time at a constant rate. What was your rate of acceleration? Initial velocity (v_i) = 0 m/s.

a. 1.6 m/s²

b. 40 m/s²

c. 3.2 m/s²

d. 6.4 m/s²

3. Two people of identical mass are running towards each other. Person A is running at 4 m/s. Person B is running at 3 m/s. Both Person A and Person B have a mass of 75 kg. What is the final momentum after they collide? Let the final momentum be positive and assume the collision is inelastic.

a. 75 m/s

b. 0.5 Ns

c. 75 Ns

d. 525 Ns

4. Using information from Question 3, who would exert a greater force upon impact: Person A or Person B?

a. Person A

b. Neither exerted a greater force on impact.

c. Person B

5. If an incompressible fluid has a volume flow rate of 0.9 m³/s, what will its speed be if it passes through an opening with a cross-sectional area of 1.8 m²?

a. 2 m/s

b. 0.95 m/s

c. 1.62 m/s

d. 0.5 m/s

6. What is the centripetal force acting on a 2000 kg car that experiences a 2.3 m/s²inward acceleration as it drives around a turn?

a. Not enough information to answer

b. 870 N

c. 13600 N

d. 4600 N

7. An ideal gas is held in a non-rigid container that is kept at a constant temperature (295 K). The pressure on the container is reduced from 50 Pa to 30 Pa. If the initial volume of the gas was 0.75 m³, what is the final volume?

a. 1.25 m³

b. 0.45 m³

c. 0.83 m³

d. 2.25 m³

8. What is the speed of a 0.07 m wave with a frequency of 400 Hz?

a. 5714 m/s

b. 0.000175 m/s

c. 28 m/s

d. 75.6 m/s

9. A thick power line of length 75 m is stretched taut between two poles, experiencing a tension force of 6250 N. The mass of the power line 750 kg. What is the maximum resonate frequency of the cable if the wavelength is exactly 1/3 the length of the cable?

a. 30 Hz

b. 1 Hz

c. 0.58 Hz

d. 25 Hz

10. How much energy is used to power a 1000 W microwave for 4 minutes?

a. 250 J

b. 4000 J

c. 240,000 J

d. 1,440,000 J

11. In an inelastic collision, momentum is conserved while the total energy is not conserved.

a. True

b. False

12. Ultrasonic waves contain frequencies that are above the threshold of human hearing.

a. True

b. False

13. In order for two identical waves to completely cancel each other out, they must be exactly one wavelength out-of-phase.

a. True

b. False

14. Doubling the resistance in a series circuit will reduce the current flow by 1/4.

a. True

b. False 15. You are watching a music concert and listening to the same concert with an ear bud. How far must you stand from the stage so that the sound waves and radio waves are synchronized in your ears?

Assume that the radio wave must travel the circumference of the Earth before you hear it. Round your answer to the nearest whole number.

Circumference of the Earth = 40,000,000 m

Speed of light = 300,000,000 m/s

Speed of sound = 345 m/s