Download Physics Final Study Guide: Practice Problems Compare the

Physics Final Study Guide: Practice Problems
d (m)
d (m)
d (m)
1) Compare the velocities the object whose motion is shown in each of the following position-time
graphs.
t (s)
t (s)
2) A sportsA car cant (s)
move 100.0 m in the first
B 4.5 s of uniform acceleration from
C rest. What is the
car’s acceleration?
3) A skateboard rider starts from rest and maintains a constant acceleration of +0.50 m/s 2 for
8.4s. What is the rider’s displacement during this time?
4) A rolling ball has an initial velocity of -1.6 m/s.
a. If the ball has a constant acceleration of -0.33m/s2, what is the velocity after 3.6 s?
b. How far did it travel in this time?
5) A toy rocket is shot straight up into the air with an initial speed of 45.0 m/s.
a. How long does it take the rocket to reach its highest point?
b. How high does the rocket rise above the ground?
6) A squirrel drops an acorn from a tree branch that is 8.00 m from the ground.
a. How long is the acorn in the air?
b. What is the acorn’s velocity when it reaches the ground?
7) In the following examples, EXPLAIN whether the situation is at equilibrium or not.
a. A person is pushing a heavy box, but the box does not move.
b. A child rides a wagon down a steep hill.
c. A car is driving at a constant speed.
8) For each of Newton’s three laws, explain what the law means AND give an example of when
you see/experience that law in real life.
a. Newton’s 1st Law
Example:
nd
b. Newton’s 2 Law
Example:
c. Newton’s 3rd Law
Example:
9) The moon's gravity pulls on an astronaut with a force of 145.6 N. If the acceleration due to the
moon's gravity is 1.6 m/s2, what is the mass of the astronaut?
10) A 12000 g boulder is dropped from a cliff.
a. How large is the force of gravity pulling on the bolder?
b. If the cliff is 34.2 m high, how long does it take for the bolder to hit the ground?
11) When catching a baseball, the ball enters the glove with a velocity of 25.5 m/s 2. It takes about
0.0045 s to come to a stop. The mass of the baseball is 0.15 kg.
a. What is the baseball’s acceleration?
b. What are the magnitude and direction of the force acting on the baseball?
c. What is the magnitude and direction of the force acting on the person who caught the
baseball?
12) A zoologist standing on a cliff aims a tranquilizer gun at a monkey hanging from a distant tree
branch. The barrel of the gun is horizontal. Just as the zoologist pulls the trigger, the monkey
lets go and begins to fall. Will the dart hit the monkey? Why or why not?
13) You take a running leap straight off of a high-diving platform. You were running at 2.3 m/s and
hit the water 2.4 s later.
a. How high was the platform?
b. How far from the edge of the platform did you hit the water?
14) An airplane traveling 1001 m above the ocean at 321 km/h is to drop a box of supplies to
refugees living below.
a. How many seconds before being directly overhead should the box be dropped?
b. What is the horizontal distance between the plane and the refugee camp when the box
is dropped?
15) A soccer ball is kicked at 35º and travels with a velocity of 12 m/s.
a. What is the flight time?
b. What is the maximum height?
c. What is the range?
16) Two opposing hockey players, one of mass 82.0 kg skating north at 6.00 m/s and the other of
mass 70.0 kg skating east at 3.00 m/s, collide and become entangled. In what direction and
with what velocity do they move after the collision?
17) A snowball with a mass of 89 g hits a snowman’s top hat and sticks to it. The hat and the
snowball, with a combined mass of 220 g, fall off together at 8.0 m/s. How fast was the
snowball moving at the moment of impact?
18) A lever is used to lift a 225-kg crate 3.2 m up to the bed of a truck. The lever is 82 percent
efficient. How much work needs to be done on the lever in order to lift the crate?
19) How much power is developed by an electric motor that moves a 500 N load a distance of 20
m in 0.10 s?
20) Will does 209 J of work to lift himself up 0.450 m. What is Will’s mass?
21) A 10.0 kg test rocket is fired vertically from Cape Canaveral. Its fuel gives it a kinetic energy of
1960 J by the time the rocket engine burns all of the fuel. If friction is ignored, to what
additional height will the rocket rise?
22) An isotope of carbon, 146C, has a half-life of 5730 y. How much of a 4.0-g sample of the
isotope will remain after 22,920 y?
23) Resolve the following vector into its perpendicular components: 20 @ 150 °
24) Find the resultant vector and equilibrant .
8@600
4@135
0
2 @ 275
25) What impulse is needed to stop a 45 kg mass traveling at a velocity of -42 m/s?
26) You push a heavy box with a mass of 55.0 kg along a smooth tile floor. The static coefficient
of friction is 0.35 and the kinetic coefficient of friction is 0.15. What force do you need to apply
to the box in order to start it moving?
27) A 5 kg friction box is accelerating along a plank inclined at 26.0° from the horizontal. The
coefficient of kinetic friction of the trunk and plank is 0.34. What is the acceleration of the box?
28) A rope which is 5.0 m long is stretched between two posts. You try to impress your friends by
doing pull ups on the rope. Your mass is 65 kg. When you hang onto the very center of the
rope, it sags 1.0 m. What is the tension on each side of the rope?
29) Review electricity and magnetism study guide.
Answers:
1) A – constant and positive
B – constant and ZERO
C – Constant and negative
2) 9.9 m/s2
3) + 18 m
4)
a. -2.8 m/s
b. -7.9 m
5)
a. 4.6 s
b. 100 m
6)
a. 1.3 s
b. 13 m/s
7)
a. Equilibrium because there is no acceleration
b. Not equilibrium because the wagon accelerates
c. Equilibrium because there is no acceleration
8)
a. Newton’s 1st Law – inertia. Object at rest remains at rest. Object in motion remains in motion
b. Newton’s 2nd Law – F = ma
c. Newton’s 3rd Law – for every force there is an equal but opposite force
9) 91 kg
10)
a. 120 N
b. 2.6 s
11)
a. -5700 m/s2
b. -860 N
c. +860 N
12) Yes. The dart and the monkey fall at the same rate (9.8 m/s2)
13)
a. 28 m
b. 5.5 m
14)
a. 14 s
b. 1200 m
15)
a. 1.4 s
c. 14 m
b. 2.4 m
16) 3.52 m/s at 66.9° East of North or 23.1°
17) 21 m/s
18) 8600 J
19) 1.0 x 105 W
20) 464 N
21) 20.0 m
22) 0.25g
23) X= -17 y=10
24) RV= 7.9 @ 80 °
EQ= 7.9 @ 260 °
25) 1900 N s
26) 190 N
27) 1.2 m/s2
28) 8.0 x 102 N