Phys 102 Final Exam

FINAL EXAM (CH 4-6)

1. A 0.031 kg aluminum bullet traveling at 459 m/s strikes an armor plate and comes to a stop. If all its energy is converted to heat that is absorbed by the bullet, what is the bullet's temperature change in degrees Celsius?

117.045 C

2. An object falls off of a pier and into the ocean (sea water) where it displaces a total volume of 4.6 cubic meters of sea water. What is the buoyant force acting on the object in newton’s?? You will need to use the mass density form of the buoyant force equation in order to work the problem in the mks system?

4.6 x 1030 x 9.8 = 46432.4 N

3. A 418 Hz sound wave travels through a substance. The wavelength of the sound wave is measured to be 1.7 meters. What is the speed of sound in the substance?

418 x 1.7 = 710.6 m/s

4. A bungee cord is stretched between two poles with a force of 437 N. The length of the cord is 27 meters and it has a mass of 5.2 kg. What is the velocity of a wave on this bungee cord?

437 x 27 = 11799

11799/ 5.2 = 2269.04^. 5 = 47.63 m/s

5. Scientists in a laboratory produce a sound wave in a simulated environment (air) with a velocity of 416 m/s. What is the temperature (in Kelvin) of the environment?

416-331 =85

85/0.6 = 141.67

273 + 141.67 = 414. 7 K

6. The air inside a bicycle tire pump has 206 joules of work done on it as 78.6 joules of heat is conducted away from it. What is the change in internal energy of the air?

78.6 – (-206) = 127.4 J

7. A submarine dives to a depth of 187?feet in the ocean. What is the force (in pounds) acting on a hatch that has an area of 3.8 square feet?? WARNING: do not use the information associated with Figure 4.26 to solve this problem because the round off error will cause you to get the wrong answer. Do not consider atmospheric pressure in your calculation, since the pressure inside of the submarine is maintained at 1 atmosphere, which offsets the 1 atmosphere of pressure that normally would be added to the gauge pressure.

1000 x 9.8 x 57 =...