The only force acting on a 2.0-kg body moving along the x axis is given by Fx = (2.0x) N, where x is in m. If the velocity of the object at x = 0 is +3.0 m/s, how fast is it moving at x = 2.0 m?
a. 4.2 m/s
b. 3.6 m/s
c. 5.0 m/s
d. 5.8 m/s
e. 2.8 m/s
[Ques. 2] A 2.0-kg body moving along the x axis has a velocity vx = 5.0 m/s at x = 0 . The only force acting on the object is given by Fx = (4.0x) N, where x is in m. For what value of x will this object first come (momentarily) to rest?
a. 4.2 m
b. 3.5 m
c. 5.3 m
d. 6.4 m
e. 5.0 m
[Ques. 3] A 10-kg block on a rough horizontal surface is attached to a light spring (force constant = 1.4 kN/m). The block is pulled 8.0 cm to the right from its equilibrium position and released from rest. The frictional force between the block and surface has a magnitude of 30 N. What is the kinetic energy of the block as it passes through its equilibrium position?
a. 4.5 J
b. 2.1 J
c. 6.9 J
d. 6.6 J
e. 4.9 J
[Ques. 4] The figure shows a distance versus time graph for an object.
The velocity of the moving object is a non-zero constant.
a.
True
b.
False
[Ques. 5] A 2.0-kg block sliding on a frictionless horizontal surface is attached to one end of a horizontal spring (k = 600 N/m) which has its other end fixed. The speed of the block when the spring is extended 20 cm is equal to 3.0 m/s. What is the maximum speed of this block as it oscillates?
a. 4.6 m/s
b. 5.3 m/s
c. 5.7 m/s
d. 4.9 m/s
e. 3.5 m/s
[Ques. 6] A 2.5-kg object falls vertically downward in a viscous medium at a constant speed of 2.5 m/s. How much work is done by the force the viscous medium exerts on the object as it falls 80 cm?
a. +2.0 J
b. +20 J
c. 2.0 J
d. 20 J
e. +40 J
[Ques. 7] How much work is done by a person lifting a 2.0-kg object from the bottom of a well at a constant speed of 2.0 m/s for 5.0 s?
a. 0.22 kJ
b. 0.20 kJ
c. 0.24 kJ
d. 0.27 kJ
e. 0.31 kJ
[Ques. 8] A 2.0-kg projectile moves from its initial position to a point that is displaced 20 m horizontally and 15 m above its initial position. How much work is done by the gravitational force on the projectile?
a. +0.29 kJ
b. 0.29 kJ
c. +30 J
d. 30 J
e. 50 J
[Ques. 9] A 5.0-kg object is pulled along a horizontal surface at a constant speed by a 15-N force acting 20 above the horizontal. How much work is done by this force as the object moves 6.0 m?
a. 78 J
b. 82 J
c. 85 J
d. 74 J
e. 43 J
[Ques. 10] When an automobile moves with constant velocity the power developed is used to overcome the frictional forces exerted by the air and the road. If the power developed in an engine is 50.0 hp, what total frictional force acts on the car at 55 mph (24.6 m/s)? One horsepower equals 746 W.
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