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WorksheetsPHYS 112- SL Midterm #2 Review
Total questions: 20
Worksheet time: 19mins
To accelerate as quickly as possible in a car from a stopped position, you would
Brake as hard as you can
Press down very lightly on the gas pedal so that your car’s wheels turn with gradually increasing acceleration, so the static force of friction propels you forward
Press the gas pedal down as quickly as you can without spinning your wheels in place so the static force of friction propels you forward
None of the above, since the force of friction cannot provide a forward force on a car.
True or False?
If Fapplied = fs you will be able to get an object at rest to slip.
True
False
Which of the following statements about terminal velocity are true? Select all that apply.
At terminal velocity, the net acceleration of the object is 0.
At terminal velocity, the magnitude of the drag force is equal to the magnitude of the weight.
At terminal velocity, the object is massless.
Terminal velocity is achieved at the highest point of motion.
Terminal velocity is inversely proportional to the square root of the cross-sectional area.
An object slides down a frictionless slope. Which of the following equations correctly shows the net force in the y-direction?
ΣFy= n-Wsin55°
ΣFy= n-Wcos55°
ΣFy= Wsin55°-n
ΣFy= n-Wcos55°-n
ΣFy= n-W
A mass m is swung in a horizontal circle from a 5 m long rope which is suspended from the ceiling as shown in the figure. The rope makes a 20° angle with the vertical axis. Find the magnitude of the angular velocity of the mass.
Impossible to determine without knowing m.
0.84 rad/s
0.71 rad/s
1.44 rad/s
2.1 rad/s
True or False? All objects undergoing uniform circular motion travel with a constant velocity.
True
False
A 1 m radius solid object that increases in angular velocity from ω1z=5 rad/s to ω2z=10 rad/s in a 5 second interval has an average angular acceleration, αz, of
1 rad/s2
25 rad/s2
-1 rad/s2
1 m/s2
-1 m/s2
Which force would be most effective in giving the rod the largest negative torque?
F1
F2
F3
F4
F5
True or False?
A crumpled ball of paper that is falling to the ground experiences a greater drag force than a flat sheet of paper floating face-down from the same height.
True
False
A ladder leans up against a wall and is not slipping. Which of the following diagrams correctly shows the forces acting on the ladder?
None of the above
A 0.50-kg toy is attached to the end of a 1.0 m long string. The toy is whirled in a horizontal circular path on a frictionless tabletop. The maximum tension that the string can withstand without breaking is 350 N. What is the maximum speed the mass can have without breaking the string? Take the string to be massless.
700 m/s
26 m/s
19 m/s
13 m/s
17 m/s
In general, what is true about the coefficients of friction?
μs > μr > μk
μk > μs > μr
μs = μk > μr
μs > μk > μr
μs > μr = μk
A 60 kg individual takes an elevator up from the first floor to the third floor. The elevator accelerates upwards for 1 s, maintains a constant acceleration for 1 s, and then slows down to rest in 1 s. If the individual in the elevator were standing on a weighing scale, how would the reading of the scale change?
The reading would decrease in the 1st second, would increase in the 2nd second, and would decrease in the 3rd second
The reading would increase in the 1st second, would increase further in the 2nd second, and would increase even further in the 3rd second
The reading would be the highest in the 1st second, would decrease in the 2nd second, and would be the lowest in the 3rd second
The reading would be the same for the 1st and third 3rd second, and lower in the 2nd second
The reading would be constant throughout
The angular velocity of a rotating object is given as a function of time as
ω(t) = 3t3 - 1/t2 rad/s. What is its angular acceleration, α, at t=2 s?
36.25 rad/s2
5.25 rad/s2
2.75 rad/s2
30.25 rad/s2
37.50 rad/s2
The distance between two planets is doubled. How does the force of gravity change?
It is doubled
It is halved
It is quadrupled
It becomes 1/4th of the original value
It stays the same
Two identical coins are rotating on a turntable, one twice as far from the axis of rotation than the other. What can be said about the centripetal force and centripetal acceleration?
The centripetal acceleration is the same while the centripetal force is lower for the coin that is further away from the axis of rotation
The centripetal acceleration as well as the centripetal force are lower for the coin that is further away from the axis of rotation
The centripetal acceleration as well as the centripetal force are higher for the coin that is further away from the axis of rotation
The centripetal acceleration is lower while the centripetal force is the same for the coin that is further away from the axis of rotation
The centripetal acceleration as well as the centripetal force are the same for both coins.
Four balls are attached to the end of a string and swung around in uniform circular motion. If each ball has the same angular velocity, which ball will experience the greatest centripetal acceleration?
A
B
C
D
They will all experience the same centripetal acceleration
True or False?
Two spherical vesicles of the same size (but one heavier than the other) diffusing through the cytoplasm of a cell at the same rate will experience the same drag force.
True
False
Which of the following statements about uniform circular motion are true? Select all that apply.
The acceleration is in the same direction as its velocity vector
The tangential acceleration is 0
The radial acceleration is directed towards the center of the circular path
The tangential velocity is 0
The net force on an object undergoing uniform circular motion is 0
If you are standing on a scale in an elevator that is accelerating downwards, how does your apparent weight compare to your true weight?
Wapparent < Wtrue
Wapparent > Wtrue
Wapparent = Wtrue
