Download Physics Test MC. Thru 10 Two wires have the same diameter and

Physics Test
MC. Thru 10
1. Two wires have the same diameter and length. One is made of copper, the other brass.
The wires are connected together end to end. When the free ends are pulled in opposite
directions, the two wires must have the same
a. stress.
b. strain.
c. ultimate strength. d. elongation e. Young’s modulus.
2. A brittle material is characterized by
a.
b.
c.
d.
high breaking strength and low Young’s modulus.
low breaking strength and high Young’s modulus.
high breaking strength and high Young’s modulus.
low breaking strength and low Young’s modulus.
3. A force F applied to each end of a steel wire (length L, diameter d) stretches it by 1.0mm.
How much does F stretch another steel wire, of length 2L and diameter 2d?
a. 0.50mm
b. 1.0mm
c. 2.0mm
d. 4.0mm
e. 0.25mm
4. A body is suspended vertically from an ideal spring. The spring is initially in its relaxed
position. The body is then released and oscillates about the equilibrium position.
The acceleration is greatest in magnitude and is directed downward when:
a.
b.
c.
d.
The spring is relaxed.
The body is at the equilibrium point.
The spring is at its maximum extension.
The spring is somewhere between the equilibrium point and the maximum extension.
5. A body is suspended vertically from an ideal spring. The spring is initially in its relaxed
position. The body is then released and oscillates about the equilibrium position.
The speed of the body is greatest when:
e.
f.
g.
h.
The spring is relaxed.
The body is at the equilibrium point.
The spring is at its maximum extension.
The spring is somewhere between the equilibrium point and the maximum extension.
6. Bernoulli’s equation is an expression of
a.
b.
c.
d.
conservation of mass.
conservation of energy.
conservation of momentum.
conservation of angular momentum.
7. Two spheres, A and B, fall through the same viscous fluid.
A and B have the same radius; A has the larger mass. Which has the larger terminal
velocity?
a. A
b. B
c. They are the same.
d. Not enough info to solve.
8. A dam holding back the water in a reservoir exerts a horizontal force on the water. The
magnitude of this force depends on
a.
b.
c.
d.
e.
the maximum depth of the reservoir.
the depth of the water at the location of the dam.
the surface area of the reservoir.
both (a) and (b).
all of the above.
9. A uniform, solid cylinder rolls without slipping down an incline. At the bottom of the
incline, the speed, v, of the cylinder is measured and the translational and rotational
kinetic energies
(K’tr , K’rot) are calculated. A hole is drilled through the cylinder along its axis and the
experiment is repeated; at the bottom of the incline the cylinder now has speed v’ and
tanslational and rotational kinetic energies K’tr and K’rot. How does the speed of the
cylinder compare with its original value?
a.
𝐾′𝑟𝑜𝑡
𝐾′𝑡𝑟
<
𝐾𝑟𝑜𝑡
𝐾𝑡𝑟
b.
𝐾′𝑟𝑜𝑡
𝐾′𝑡𝑟
=
𝐾𝑟𝑜𝑡
𝐾𝑡𝑟
c.
𝑲′𝒓𝒐𝒕
𝑲′𝒕𝒓
>
𝑲𝒓𝒐𝒕
10. When both are expressed in terms of SI base units, torque has the same unit as
a. angular acceleration
b. angular momentum
c. force
d.energy
e. rotational inertia
f. angular velocity
𝑲𝒕𝒓
11. An object of mass m drops from rest a little above the earth’s surface for a time t. Ignore
air resistance. After time t the magnitude of its momentum is
a. mgt2
b. mgt
c. mg√𝑡
d. √𝑚𝑔𝑡
e.
𝑚𝑔𝑡 2
2
12. Two particles A and B of equal mass are located at some distance from each other.
Particle A is at rest while B moves away from A at speed v. What happens to the center
of mass of the system of two particles?
a.
b.
c.
d.
e.
It does not move.
It moves with a speed 1/2v away from A.
It moves with a speed v away from A.
It moves with a speed of v toward A.
It moves with a speed 1/2v toward A.
13. A simple catapult, consisting of a leather pouch attached to rubber bands tied to two forks
of a wooden Y, has a spring constant, k, and is used to shoot a pebble horizontally. When
the catapult is stretched by a distance, d, it gives a pebble of mass, m, a launch speed, v.
What speed does the catapult give a pebble of mass m/3 when stretched to a distance d?
a. √3𝑣
b. 3v
c. 3√3𝑣
d. 9v
e. 27v
14. A hiker descends from the South Rim of the Grand Canyon to teh Colorado River.
During his hike, the work done by gravity on the hiker is
a.
b.
c.
d.
e.
positive and independent of the path taken
negative and depends on the path taken
positive and depends on the path taken
negative and independent of the path taken
zero
15. If a kangaroo on earth can jump from a standing start so that its feet reach a height, h,
above the surface, approximately how high can the same kangaroo jump from a standing
start on the moon’s surface? Gravity on the moon is about 1/6 earth’s gravity.(Assume
the kangaroo has an oxygen tank and pressure suit with negligible mass.)
a. h
b. 6h
c. 1/6h
d. 36h
e. 1/36h
f. √6ℎ
16. An object moving in a circle at a constant speed has an acceleration that is
a.
b.
c.
d.
17.
in the direction of motion
zero
away from teh center of the circle
toward the center of the circle
(1) Its acceleration is constant.
(2) Its radial acceleration component is constant in magnitude.
(3) Its tangential acceleration component is constant in magnitude.
An object is in nonuniform circular motion with constant angular acceleration.
Identify the correct statement.
a. 1 only b. 2 only
c. 3 only
d. 1, 2, and 3
a. 2 and 3
f. 1 and 2
g. 1 and 3
h. none of them
18. A boy swings in a tire swing. When is the tangential acceleration the greatest?
a.
b.
c.
d.
at the highest point of the motion
at the lowest point of the motion
at a point neither highest nor lowest
it is constant
19. A space probe leaves the solar system to explore interstellar space. Once it is far from
any stars, when must it fire its rocket engines?
a.
b.
c.
d.
e.
All the time, in order to keep moving.
Only when it wants to speed up.
When it wants to speed up or slow down.
Only when it wants to turn.
When it wants to speed up, slow down, or turn.
20. A woman stands on a bathroom scale in an elevator that is not moving. The scale reads
500 N. The elevator then moves downward at a constant velocity of 4.5 m/s. What does
the scale read while the elevator descends with constant velocity?
a.
b.
c.
d.
e.
100 N
250 N
450 N
500 N
750 N
21. To make an object start moving on a surface with friction requires
a.
b.
c.
d.
less force than to keep it moving on the surface.
the same force as to keep it moving on the surface.
more force than to keep it moving on the surface.
a force equal to the weight of the object.
22. Which of these is not a long-range force?
a.
b.
c.
d.
the force that makes raindrops fall to the ground
the force that makes a compass point north
the force that person exerts on a chair while sitting
the force that keeps the Moon in its orbital path around the Earth
23. When a force is called a “normal” force, it is
a.
b.
c.
d.
e.
the usual force expected given the arrangement of a system.
a force that is perpendicular to the surface of the earth at any given location.
a force that is always vertical.
a contact force perpendicular to the contact surfaces between two solid objects.
the net force acting on a system.
24. Within a given system, the internal forces
a. are always balanced by the external forces.
b. all add to zero.
c. are determined only by subtracting the external forces from the net force on the
system.
d. determine the motion of the system.
e. can never add to zero
25. Two projectiles launched with the same initial speed but at different launch angles 30°
and 60° land at the same spot. Ignore air resistance.
Which has a longer time of flight?
a. projectile launched at 30°
b. projectile launched at 60°
c. They are equal.
26. A ball is thrown into the air and follows a parabolic trajectory. Point A is the highest
point in the trajectory and point B is a point as the ball is falling back to the ground.
Choose the correct relationship between the speeds and the magnitudes of the
acceleration at the two points.
a.
b.
c.
d.
𝑣𝐴 > 𝑣𝐵 and 𝑎𝐴 = 𝑎𝐵
𝑣𝐴 < 𝑣𝐵 and 𝑎𝐴 > 𝑎𝐵
𝑣𝐴 = 𝑣𝐵 and 𝑎𝐴 ≠ 𝑎𝐵
𝒗𝑨 < 𝒗𝑩 and 𝒂𝑨 = 𝒂𝑩
27. A person stands on the roof garden of a tall building with one ball in each hand. If the
red ball is thrown horizontally off the roof and the blue ball is simultaneously dropped
over the edge, which statement is true?
a. Both balls hit the ground at the same time, but the red ball has a higher
speed just before it strikes the ground.
b. The blue ball strikes the ground first, but with a lower speed than the red ball.
c. The red ball strikes the ground first with a higher speed than the blue ball.
d. Both balls hit the ground at the same time with the same speed.
28. A kicker kicks a football from the five yard line to the 45-yard line(both on the same
half of the field). Ignoring air resistance, where along the trajectory is the speed of the
football a minimum?
a.
b.
c.
d.
e.
at the 5-yard line, just after the football leaves the kicker’s foot
at the 45-yard line, just before the football hits the ground
at the 15-yard line, while the ball is still going higher
at the 35-yard line, while the ball is coming down
at the 25-yard line, when the ball is at the top of its trajectory