An ore car of mass 4 900 kg rolls downhill on tracks from a mine. At the end of the tracks, 13.5 m lower in elevation, is a spring with k = 410 000 N/m. How much is the spring compressed in stopping the ore car? Ignore friction.
a. 1.26 m
b. 0.889 m
c. 1.78 m
d. 0.568 m
e. 0.484 m
[Ques. 2] A proton is released such that its initial velocity is from right to left across this page. The proton's path, however, is deflected in a direction toward the bottom edge of the page due to the presence of a uniform magnetic field. What is the direction of this field?
a. out of the page
b. into the page
c. from bottom edge to top edge of the page
d. from right to left across the page
[Ques. 3] Suppose a 0.45-kg mass on a spring-loaded gun that has been compressed 0.10 m has elastic potential energy of 1.50 J. How high above the spring's equilibrium point can the gun fire the mass if the gun is fired straight up?
a. 0.34 m
b. 0.58 m
c. 0.24 m
d. 3.2 m
e. 33 m
[Ques. 4] An electron is accelerated from rest through 2300 V and then enters a region of uniform magnetic field with magnitude 1.25 T. What is the magnitude of the maximum magnetic force acting on the electron?
a. 5.68E12 N
b. 4.02E12 N
c. 4.07E12 N
d. 2.03E12 N
[Ques. 5] Suppose a 0.70-kg mass on a spring that has been compressed 0.26 m has elastic potential energy of 2.20 J. How much further must the spring be compressed to triple the elastic potential energy?
a. 0.45 m
b. 0.71 m
c. 0.78 m
d. 0.19 m
e. 0.52 m
[Ques. 6] A proton is circling the Earth above the magnetic equator, where Earth's magnetic field is directed horizontally north and has a magnitude of 4.00 108 T. If the proton is moving at a speed of 2.7 107 m/s, how far above the surface of the Earth is the proton? Earth's radius is 6.38 106 m, a proton's mass is 1.67 1027 kg, and its charge is 1.6 1019 C.
a. 7.05E+6 m
b. 1.34E+7 m
c. 1.03E+8 m
d. 6.65E+5 m
[Ques. 7] Suppose a 0.74-kg mass on a spring that has been compressed 0.100 m has elastic potential energy of 1.20 J. What is the spring constant?
a. 178 N/m
b. 320 N/m
c. 240 N/m
d. 24.0 N/m
e. 74.0 N/m
[Ques. 8] The magnetic field of the Earth at a particular location is directed vertically downward with magnitude of 40.0 T. An electron is moving horizontally toward the west in this field with a speed of 5.2 106 m/s. What are the direction and magnitude of the magnetic force the field exerts on the electron? (e = 1.6 1019 C)
a. 3.33E17,south
b. 3.33E17,north
c. 2.08E20,south
d. 2.08E20,north
[Ques. 9] The oxygen molecule (O2) may be regarded as two masses connected by a spring. In vibrational motion, each oxygen atom alternately approaches, then moves away from the center of mass of the system. If each oxygen atom of mass m = 2.67 1026 kg has a vibrational energy of 1.6 1021 J and the effective spring constant is 86 N/m, then what is the amplitude of oscillation of each oxygen atom?
a. 3.2E11 m
b. 1.6E11 m
c. 1.1E11 m
d. 6.1E12 m
e. 4.3E12 m
[Ques. 10] A proton moves through a magnetic field of magnitude 1.40 T with speed 5.00 106 m/s. What is the magnitude of the maximum acceleration of the proton? The mass of a proton is 1.67 1027 kg, and its charge is 1.6 1019 C.
a. 3.42E+14 m/s
b. 6.71E+14 m/s
c. 3.35E+21 m/s
d. 1.71E+21 m/s
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