The sum of vectors A and B is
a.
b.
c.
d.
[Ques. 2] An airplane moves 140 m/s as it travels around a vertical circular loop which has a 1.0-km radius. What is the magnitude of the resultant force on the 70-kg pilot of this plane at the bottom of this loop?
a. 2.1 kN
b. 1.4 kN
c. 0.69 kN
d. 1.5 kN
e. 1.3 kN
[Ques. 3] An airplane travels 80 m/s as it makes a horizontal circular turn which has a 0.80-km radius. What is the magnitude of the resultant force on the 75-kg pilot of this airplane?
a. 0.69 kN
b. 0.63 kN
c. 0.66 kN
d. 0.60 kN
e. 0.57 kN
[Ques. 4] A race car travels 40 m/s around a banked (45 with the horizontal) circular (radius = 0.20 km) track. What is the magnitude of the resultant force on the 80-kg driver of this car?
a. 0.68 kN
b. 0.64 kN
c. 0.72 kN
d. 0.76 kN
e. 0.52 kN
[Ques. 5] A baseball outfielder throws a baseball of mass 0.15 kg at a speed of 40 m/s and initial angle of 30. What is the kinetic energy of the baseball at the highest point of the trajectory?
[Ques. 6] The figure shows a distance vs. time graph of an object with three distinct regions, I, II, and III.
The objects speed is greatest in region I.
a.
True
b.
False
[Ques. 7] A moving particle is subject to conservative forces only. When its kinetic energy decreases by 10 J, what happens to its mechanical energy?
a. It increases by 10 J.
b. It decreases by 10 J.
c. It increases, but not necessarily by 10 J.
d. It decreases, but not necessarily by 10 J.
e. It remains the same.
[Ques. 8] The figure shows a distance vs. time graph of an object with three distinct regions, I, II, and III.
The object is never at rest.
a.
True
b.
False
[Ques. 9] A baseball is thrown and lands 120 m away. While the ball is in flight, assuming the effect of air friction is negligible, which of the following is true?
a. At maximum height the ball has its greatest kinetic energy.
b. The horizontal component of the baseball's kinetic energy is constant.
c. The vertical component of the baseball's kinetic energy is constant.
d. The mechanical energy of the baseball is greater when nearer to the ground.
e. No answer above is correct.
[Ques. 10] After a skydiver reaches terminal velocity,
a. the force of gravity no longer performs work on the skydiver.
b. work performed by the force of gravity is converted into gravitational potential energy.
c. gravitational potential energy is no longer available to the system of the skydiver plus the Earth.
d. gravitational potential energy is converted into thermal energy.
e. thermal energy is converted into gravitational potential energy.
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