A champion athlete can produce one horsepower (746 W) for a short period of time. The number of 16-cm-high steps a 70-kg athlete could ascend in one minute while expending one horsepower is
a.
4.
b.
7.
c.
65.
d.
408.
e.
4567.
[Ques. 2] A champion athlete can produce one horsepower (746 W) for a short period of time. If a 70-kg athlete were to bicycle to the summit of a 500-m high mountain while expending power at this rate, she would reach the summit in ____ seconds.
a.
1
b.
460
c.
500
d.
1000
e.
35,000
[Ques. 3] A champion athlete can produce one horsepower (746 W) for a short period of time. If a 70-kg athlete were to bicycle to the summit of a 500-m high mountain while expending power at this rate, she would have used at least ____ J of energy.
a.
746
b.
3.43 10
5 c.
3.73 10
5 d.
7.46 10
5 e.
2.61 10
7
[Ques. 4] If the scalar (dot) product of two vectors is negative, it means that
a.
there was a calculator error.
b.
the angle between the vectors is less than 90 degrees.
c.
the angle between the vectors is 90 degrees.
d.
the angle between the vectors is greater than 270 degrees.
e.
the angle between the vectors is between 90 and 180 degrees.
[Ques. 5] The only force acting on a 2.0-kg body as it moves along the
x axis is given by
Fx = (12 2.0
x) N, where
x is in m. The velocity of the body at
x = 2.0 m is 5.5
m/s. What is the maximum kinetic energy attained by the body while moving in the +
x direction?
a.
36 J
b.
39 J
c.
43 J
d.
46 J
e.
30 J
[Ques. 6] The only force acting on a 2.0-kg body moving along the
x axis is given by
Fx = (2.0
x) 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. 7] The only force acting on a 1.6-kg body as it moves along the x axis is given in the figure. If the velocity of the body at x = 2.0 m is 5.0 m/s, what is its kinetic energy at x = 5.0 m?
a.
52 J
b.
44 J
c.
36 J
d.
60 J
e.
25 J
[Ques. 8] A 1.5-kg object moving along the x axis has a velocity of +4.0 m/s at x = 0. If the only force acting on this object is shown in the figure, what is the kinetic energy of the object at x = +3.0 m?
a.
18 J
b.
21 J
c.
23 J
d.
26 J
e.
8 J
[Ques. 9] 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 = (4.0
x) 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. 10] A 3.0-kg block is dragged over a rough horizontal surface by a constant force of 16 N acting at an angle of 37 above the horizontal as shown. The speed of the block increases from 4.0 m/s to 6.0 m/s in a displacement of 5.0 m. What work was done by the friction force during this displacement?
a.
34 J
b.
64 J
c.
30 J
d.
94 J
e.
+64 J
Quick Reply
