# Physics 20 * Cumulative Review

advertisement ```Physics 20 – Cumulative Review
Name: ______________________________________
1. A dog walks 45 m south, turns, and walks 45 m 23o S of W. Find the displacement of the dog.
70m [52̊ S of W]
2. A rubber bullet is fired horizontally with a velocity of 875 m/s at a target on the ground 250
metres away. From what height was the bullet fired? 0.400 m
3. A football is kicked into the air with a velocity of 30.0 m/s at an angle of 35.0o to the horizontal.
How far will the football travel horizontally? 86.2 m
4. A mean angry person throws a stinky moldy ball of cheese at an angle of 32o from the roof of
his/her home which is 9 m from the ground. He/she throws this vile ball of cheese with a
velocity of 22 m/s. If the unsuspecting person is 14 m from the house, does the angry person hit
his/her target? (hint: What is the horizontal distance from the house that the cheese will hit the
ground?) No, they will not hit the person.
5. A 16 year old is driving a dirty old beater through Strathmore. As the teenager leaves the limit
of the town, he/she speeds up at a constant acceleration of 1.00 m/s2. While accelerating at this
rate, he/she travels 417.2 m [E] in a time of 27.0 s. What velocity did the old beater get up to in
this time? 29.0 m/s
6. A cute little wibblet is initially at rest. The wibblet then decides to accelerate to a velocity of 10
m/s [W] in 2.50 s. If during this time the displacement of the wibblet is 12.5 m [W], what is the
rate of the acceleration? 4 m/s2
7. A pilot wants to fly west (the destination is directly west). If the plane has an airspeed of 95
m/s, and there is a 25 m/s wind blowing north, in what direction must the pilot head the plane?
15° S of W
8. A 118 N ball of cheese is accelerated at a rate of 4.0 m/s2 by a net force. What is the magnitude
of the net force? 48 N
9. A 2.27 x 103 kg Hummer accelerates uniformly from 10.0 m/s east to 32.0 m/s east. During this
acceleration the van travels 129 m. What is the net force acting on the van during this
acceleration? 𝟖. 𝟏𝟑 × 𝟏𝟎𝟑 𝑵
10. A 156 kg crate of beeswax is at rest on inclined plane. If the inclined plane makes an angle with
the horizontal of 21.0o, what is the normal force acting on the object? 𝟏. 𝟒𝟑 × 𝟏𝟎𝟑 𝑵, [𝟐𝟎𝟏°]
11. Two masses are attached at ends of a string that is hung over a frictionless pulley. If the mass on
the left of the pulley is 3.0 kg and the mass to the right of the pulley is 5.0 kg, what is the
acceleration of the 3.0 kg mass and in what direction will it travel? 2.5 m/s toward the 5.0 kg
mass
12. A 111 N wagon full of Norbert’s rock collection is pulled west along a horizontal surface with a
force of 55.5 N acting at an angle of 43.0o. If the coefficient of kinetic friction is 0.09, what is the
acceleration? 2.7 m/s2
13. A 525 N box of crayons is sliding down a 33o incline. If the force of friction along the incline is
50 N, what is the acceleration of the box? 4.4 m/s down the incline
14. A 1.00kg block is lying on a horizontal surface. The block is attached to two light ropes that pass
over light, frictionless pulleys to mass A (4.00kg) and mass B (2.00kg). If the coefficient of
kinetic friction on the block is 0.5, what is the acceleration on the system? 2.1 m/s2 toward A
15. A 675 N punk brings his scale onto an elevator and stands on it. As the elevator begins to fall, he
sees that the scale reads 555 N. Find the acceleration of the elevator as it begins to fall. 2.12
m/s2 down
16. A wagon with rubber tires rests on a horizontal, wet surface. Calculate the mass of the wagon if
an applied force of 67 N [forward] would cause the wagon to start moving. The coefficient of
static friction is 0.6 and the coefficient of kinetic friction is 0.5. 11 kg
17. While standing on a horizontal frictionless surface, a 45.0kg baseball pitcher throws a 3.0kg
fastball to his right. During the throw the ball was accelerated horizontally through a distance of
0.60m from rest to a velocity of 9.6 m/s. Calculate the acceleration of the pitcher when the ball
is released.
18. Bob is moving a steel box in shop class on a steel workbench. He pushes against the box with a
force of 25N. Will anything happen? What is the magnitude of the force of friction on the box? If
the box has a mass less than or equal to 6.2 kg, the box will move.
19. Two blocks of identical material are connected by a light rope on a level surface. An applied
force of 55N causes the blocks to accelerate. While in motion, the magnitude of the force of
friction on the blocks is 44.1N. The force of friction on the 10-kg block has a magnitude of
14.7N. Calculate the tension in the rope connecting the two blocks. 0.36 m/s2 [right]
20. A 5.0 kg bucket of manure is being pushed up a 28˚ incline with an applied force of 50N. If it
accelerates at 2.6 m/s2, what is the coefficient of kinetic friction? 0.75
21. Suppose that two objects attract each other with a gravitational force of 16 N. If the mass of
both objects was doubled, and if the distance between the objects was doubled, then what
would be the new force of attraction between the two objects? 4.0 N
22. Suppose that you have a mass of 70 kg. How much mass must another object have in order for
your body and the other object to attract each other with a force of 1-Newton when separated
by 10 meters? 𝟐. 𝟏𝟒 × 𝟏𝟎𝟏𝟎 𝑵
23. A little furry creature (let’s just call it a furrythinga) climbs to the top of a mountain (let’s just
call it Mount Yournevercomingdowna). At the top of the mountain, it steps on a bathroom scale
and sees that it weighs 267 N. If the height of this mountain is 1.179 x 102 m, what is the mass of
the creature? 27.2 kg
24. The dwarf planet Pluto has three moons, Nix, Hydra, and Charon. Nix has a mass of 2.00 x 1018
kg and its mean distance from Pluto is 5.111 x 107 m. Hydra has a mass of 1.50 x 1018 kg and its
mean distance from Pluto is 6.674 x 107m. Charon has a mass of 1.52x 1021 kg and its mean
distance from Pluto is 1.96 x 107m. The mass of Pluto is 1.21 x 1022 kg. Determine the net force
acting on Pluto from the gravitational force of the three moons when the Nix and Hydra are
opposite to Charon. 𝟑. 𝟏𝟗 × 𝟏𝟎𝟏𝟖
25. A 81-kg person is standing on a bathroom scale in an elevator (sounds like a perfectly
reasonable thing to be doing). The elevator descends with an acceleration of 6.4 m/s2. Calculate
the true weight and apparent weight of the dude. True: 795 N; Apparent: 276 N
26. An adventurer enters a contest that demands the contestant must take a picture of a scale
reading of his/her weight and it must be exactly 733.5N. If the adventurer has a mass of 75kg,
how high must the person climb (above sea level) in order to make his/her weight exactly 733.5
N? 𝟐. 𝟐𝟔 × 𝟏𝟎−𝟓
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