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Practice Physics Final (Fall)
Units
1) Convert 1.6 km into centimeters
A) 0.0016 cm B) 1600 cm C) 0.000016 cm
D) 160000 cm
2) Convert 35.6 millimeters into km
A) 0.000356 km B) 35600 km C) 0.0000356 km
E) none of these
D) 3560000 km
E) none of these
3) Convert 25 cm3 into mL
A) 25 mL B) 2.5 mL C) 0.25 mL D) 0.025 mL E) none of these
Kinematics
4) The fastest airplane is the Lockheed SR-71. If an SR-71 flies 10.0 miles in 15.3 sec,
what is its average speed?
A) 0.654 mph B) 39.2 mph C) 780 mph D) 1430 mph E) 2350 mph
5) How fast will a motorcycle starting at rest go after 5 seconds if its acceleration is 3 m/s2?
A) 7 m/s B) 12 m/s C) 15 m/s D) 18 m/s
E) none of these
6) How long does it take for a sport car at rest to reach 27 m/s if its acceleration is 9 m/s2?
A) 1.0 s B) 2.0 s C) 3.0 s D) 4.0 s
E) none of these
7) You toss a tennis ball from the window of you car backwards at 2 m/s. If the car is
traveling at 30 m/s, what is the speed of the tennis ball relative to the ground?
A) 28 m/s B) 19 m/s C) 15 m/s D) 32 m/s
E) none of these
8) The typical takeoff speed for jetliners is 240 km/hour. If it accelerates uniformly for 15
seconds, how long must the runway be?
A) 240 m
B) 500 m
C) 720 m
D) 980 m
E) none of these
Laws of Motion
9) If an object in motion has no net force, it will:
A) slow down B) speed up C) be at rest D) remain at the same velocity
E) not enough information
10) What is the acceleration of a 5 kg object with a 10 N net force?
A) 50 m/s2 B) 2 m/s2 C) 25 m/s2 D) 10 m/s2 E) none of these
11) A tow truck exerts a 4200 N net force on a car. If the car accelerates at 3.0 m/s2, what is
its mass?
A) 1600 kg B) 1800 kg C) 2000 kg D) 2400 kg E) none of these
12) A 50.0 kg boy is accelerating on a skateboard at 2.00 m/s2. If he tosses his 2 kg helmet
his acceleration will be:
A) 1.96 m/s2 B) 2.00 m/s2 C) 2.04 m/s2 D) 2.08 m/s2
E) none of these
13) A swimmer pushes herself from the wall at the end of the pool. The swimmer and the
wall will experience equal:
A) but opposite momentum B) but opposite acceleration C) kinetic energy
D) but opposite forces
E) none of these
Net Force
14) An 1850 kg car is moving to the right at a constant speed of 20 m/s. What is the net force
on the car?
A) 93 N
B) 213 N
C) 3700 N
D) 0 N
E) none of these
15) An airplane is subject to two forces, 45000N (Fengine) in the direction of motion and
15000N cross wind (Fwind) at 90, what is the net force?
A) 33000 N B) 47000 N C) 54000 N D) 68000 N E) none of these
16) A 5 kg textbook is pushed by 60 N force across the table. Assuming the friction force is
20 N, what is its acceleration?
A) 8 m/s2 B) 4 m/s2 C) 10 m/s2 D) 16 m/s2 E) none of these
17) What is the minimum force required to move a 50 kg box? (use a coefficient of static
friction, s, of 0.4)
A) 100 N
B) 200 N
C) 300 N
D) 400 N
E) none of these
Gravity
18) What is the weight of a 70 kg person?
A) 9.8 N
B) 70 N
C) 98 N
D) 700 N
E) none of these
19) If a person weights 650 N, what is his/her mass?
A) 65 kg
B) 75 kg
C) 98 kg
D) 125 kg
E) none of these
20) What is the gravitational force between two persons each with a mass of 70 kg when they
are 2 meters apart? (G = 6.67 x 10-11 N m2/kg2)
A) 4.1 x 1013 N B) 2.7 x 10-8 N C) 1.8 x 1013 N D) 8.2 x 10-8 N E) none of these
21) An object in free fall is traveling at 30 m/s at one instant. Two seconds later its speed is:
A) 35 m/s
B) 45 m/s
C) 55 m/s
D) 65 m/s
E) none of these
22) Ball bearings are made by letting spherical drops of molten metal fall and solidify as they
fall. If a bearing takes 4 seconds to solidify, how high must the release point be?
A) 80 m
B) 40 m
C) 15 m
D) 6 m
E) none of these
23) What is the impact speed of a ball bearing when it hits the ground if it falls 20 meters?
A) 20 m/s
B) 35 m/s
C) 200 m/s
D) 135 m/s
E) none of these
Work and Energy
24) Decreasing the velocity of a 2000 kg car from 30 m/s to 15 m/s reduces its kinetic energy
by:
A) 25 %
B) 50 %
C) 75 %
D) 100 % E) none of these
25) If you carry a bag of groceries to the 2nd floor, how much more work do you do than
when you carry then to the 1st floor?
A) same
B) twice as much
C) four times as much D) none of these
26) The work done by gravity on a 10 kg bowling ball rolling along an alley for 10 meters is:
A) 1000 N
B) None, there is no force of gravity acting on the bowling ball
C) Is canceled by the work done by the normal force
D) None, there is no component of gravity along the direction of motion
E) none of these
27) What is the average power supplied by a 70 kg person going up the stairs rising vertically
5.0 m in 5.0 seconds?
A) 250 W
B) 700 W
C) 1750 W D) 2500 W
E) none of these
28) John pushes a container for 10 meters using a 200 N force in 10 seconds. Joe pushes the
container the same distance using a 500 N force in 20 seconds. Which one is more
powerful?
A) John
B) Joe
C) the same D) more info is needed
Momentum
29) A motorcycle going at 30 m/s had a momentum of 7110 kg m/s. What is its mass?
A) 213300 kg B) 213 kg C) 237 kg
D) 294 kg
E) none of these
30) If the motorcycle from the previous problem crashes into a wall and stops in 0.9 seconds,
how force acted on it to bring it to a stop?
A) 7900 N
B) 861 N
C) 2364 N
D) 6400 N
E) none of these
31) Two cars with the same mass and initial speed (v) collide head on. What is the final
velocity if the collision is perfectly elastic?
A) v/2
B) 2v
C) 0
D) 4v
E) none of these
32) The reason airbags minimize injuries during a collision is:
A) the final velocity is smaller
B) the change in momentum is smaller
C) the time of impact is reduced
D) the time of impact is increased
E) none of these
33) Assuming a fullback is more massive than a running back and both run at the same speed,
the force required to stop the running back in the same amount of time is:
A) greater
B) smaller
C) the same D) more info needed E) none of these
34) A 90 kg fullback running at 5.0 m/s collides head on at the goal line with a 110 kg
defender. Assuming a perfectly inelastic collision, how fast must the defender run to
ensure the fullback doesn’t score?
A) 4.1 m/s
B) 4.5 m/s
C) 5.0 m/s
D) 5.4 m/s E) none of these
Circular Motion
35) Which children experience the biggest tangential speed in a merry-go-round, those on the
inside or outside track?
A) inside
B) outside
C) same
D) not enough info E) none of these
36) A cylindrical tub of a washing machine has a radius of 0.34 m. During the spin cycle the
wall of the tub rotates with a tangential speed of 5.5 m/s. What is the centripetal
acceleration?
A) 57 m/s2
B) 68 m/s2
C) 74 m/s2
D) 89 m/s2
E) none of these
37) How would the tangential speed of the Moon orbiting the Earth change if the mass of the
Earth increased by 4?
A) It would not change
B) Twice C) Four times
D) Not enough info
38) To minimize the force required to tighten a bolt using a wrench, the force must be
applied:
A) perpendicular to the axis of rotation
B) parallel to the axis of rotation
C) At right angles
D) As close enough as possible
39) John applies a force of 50 N at the end of a 0.3 m wrench perpendicular to the axis of
rotation of a bolt. In the same way, Joe applies a 75 N force using a 0.2 wrench. Who
provided the biggest torque?
A) John
B) Joe
C) the same
D) Not enough info
Fluids
40) The Guinness Record for the deepest scuba dive is 320 m, what is the gage pressure at
such depth? (ρsea = 1025 kg/m3)?
A) 2.3x106 Pa B) 3.3x106 Pa C) 4.3x106 Pa D) 5.3x106 Pa E) none of these
41) A water hose with a 2.0 cm inside diameter delivers water at 0.2 m/s. What should be the
exiting area such that the exiting velocity is 0.5 m/s?
A) 1.3x10-4 m2
B) 1.9x10-4 m2 C) 2.6x10-4 m2
D) 3.2x10-4 m2 E) none of these
42) A balloon is inflated with 0.1 kg helium. If the radius of the balloon (spherical) is 0.5 m,
what is the density of helium?
A) 0.12 kg/m3
B) 0.16 kg/m3
C) 0.19 kg/m3
D) 0.22 kg/m3 E) none of these
43) If you press the helium balloon with one of your fingers touching 0.0005 m2 and inside
internal pressure is 4000 Pa, what is the force you feel?
A) 0.5 N
B) 1.0 N
C) 1.5 N
D) 2.0 N
E) none of these
Heat
44) On the Moon the surface can get as hot as 375 K. What is this temperature in degrees
Fahrenheit?
A) 75F
B) 113F
C) 187F
D) 216F
E) none of these
45) A 65 kg jogger can generate 8.0 x 105 J of energy, how much would the jogger’s
temperature rise if heat is not removed from the jogger’s body? (cp.b = 3500 J/kgºC)
A) 3.5C
B) 4.5C
C) 5.5C
D) 6.5C
E) none of these
46) If all of the energy in the previous problem (generated by the jogger) was removed by
sweating (evaporation), how much water is needed? (Lv = 2.26 x 106 J/kg)
A) 0.15 kg
B) 0.25 kg
C) 0.35 kg
D) 0.45 kg
E) none of these