Download Applying Newton second law to horizontal motion practice problems

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Applying Newton’s Second Law to horizontal motion practice problems
1. The unit used to measure force is ................... . This unit is equivalent to the SI units .................
2. One Newton is described as the force required to give .............................................................................
3. Let’s assume that the wheels of a 5-kg car apply 10 N [E] of force. What is acceleration if friction and
drag are negligible?
4. What is the net force and acceleration if the wheels of the 5-kg car apply 10
N [E] but a 1-kg parachute applies 7 N [W] in the other direction?
5. A rocket is added to the car and applies an additional force of 10 N [E]. The
wheels still apply 10 N [E]. What is the net force if the parachute continues to
apply 7 N in the other direction? The total mass of the car, rocket and parachute
is 10 kg. What is the acceleration?
6. A net force of 15 N is exerted on an encyclopedia to cause it to accelerate at a rate of 5 m/s2. Determine
the mass of the encyclopedia.
7. A net force of 25 N [south] acts on a wagon of mass 75 kg. Determine the acceleration (Remember acceleration is a
vector quantity) of the wagon.
8. An object of mass 15.0 kg is accelerated from rest to a velocity of 10.0 m/s in a time of 5.00 s. What net force is
acting on the object?
9. A net force of 3850 N accelerates a car for 7.00 s from rest to 54.6 km/h (convert to m/s) . What is the car's
mass?
10. An object is given an acceleration of 2.50 m/s2 by a net force of 5.00 N .Calculate the mass of the object.
11. Suppose that a sled is accelerating at a rate of 2 m/s2. If the net force is tripled and the mass is doubled,
then what is the new acceleration of the sled?
12. A net force F is required to give an object with mass m an acceleration a. If a net force 6F is applied to
an object with mass 2m, what is the acceleration on this object?
13. Suppose that a sled is accelerating at a rate of 5 m/s2. If the net force is tripled and the mass is halved,
then what is the new acceleration of the sled?
14. What force is needed to accelerate a 0.540 kg toy truck from 1.00 m/s to 2.13 m/s over a distance of
0.815 m to the east?
15. A net force of 8.0 N accelerates a 4.0-kg roast from 10 m/s [forward] to 18 m/s [forward]. For how long was the net
force applied?
16. A 810-kg car accelerates from rest to 27 m/s in a distance of 120 m. What is the magnitude of the
average net force acting on the car?
17. A car has a mass of 1500 kg. What net force is needed to accelerate the car from 5.00 m/s to 25.0 m/s in 10.0 s?
force of engine
m = 4200 kg
= 6397 N north
force of friction
= 5184 N south
18. Find the truck's acceleration.
19. A cart of mass 8.5 kg is pushed along a factory floor by an applied force of 27.0 N against a frictional
force of 9.0 N. What is the car’s acceleration?
20. A 60.0 kg block rests on a rough horizontal surface and experiences a force of 1200 N. What is the force
due to friction if the block accelerates at 4.00 m/s2 south?
21. A crate of mass 26.0 kg is moved along a level floor by an applied force of 150 N against a frictional
force of 50.0 N. Determine the acceleration of the crate.
22. A net force of 3.0 N is applied to a small toy of mass 0.20 kg, initially at rest. What is the magnitude of the velocity
of the toy after 2.0 s?
23. A box of mass 5.0 kg is moving on a smooth ice surface with a velocity of 6.0 m/s . A constant force is applied for
3.0 s and the box reaches a final velocity of 12 m/s. What was the applied force?
24. A force of 300 N applied to a stove on a kitchen floor produces an acceleration of 5.0 m/s2. If the magnitude of the
frictional force is 100 N, what is the mass of the stove?
25. A lawnmower’s handle is pushed at an angle of 30.0 to the horizontal. If the handle is pushed with a force of 92.0
N and it experiences a force of friction of 32.0 N. If the mass of the lawnmower is 50.0 kg, what is the acceleration
of the lawnmower?
26. An airboat with mass 4.50 102 kg, including
passengers, has an engine that produces a net
horizontal force of 8.14 102 N, after
accounting for forces of resistance.
(a) Find the acceleration of the airboat.
(b) Starting from rest, how long does it take the
airboat to reach a speed of 16.0 m/s?
(c) After reaching this speed, the pilot turns off the engine and drifts to a stop over a distance of 50.0
meters. Find the resistance force, assuming it's constant.
27. A large steel ball bearing of mass 1.0 kg rolls down an inclined track where the force of friction is 2.0 N [up the
track]. The component of the force of gravity down the track is 5.0 N. What is the acceleration of the ball bearing?
28. A sidewalk offers a resistive force of 15.0 N to a 2.5 kg skateboard which is pushed with an applied force of 25.0
N. Calculate the acceleration of the board.
29. A truck of mass 4.5 x 103 kg is originally at rest is acted on by an applied force of 2.0 x 103 N. If there is a
frictional force on the truck of 500 N, find:
a. The net force on the truck
b. Its acceleration
c. Its speed after 4.0 s.
30. An 8.0 kg rocket fired horizontally encounters an air resistance of 4.9 N. The force supplied by the rocket engine is
60.9 N.
a. What is the net force accelerating the rocket
b. What is the horizontal acceleration imparted to the rocket?
31. A wagon of mass 4.2 x 104 kg rolls from rest through 50.0 m in 17.0 s. If there is a frictional force of 5.0 x 103 N
on the wagon, calculate:
a. The wagon acceleration
b. The net force on it
c. The applied force
d. The wagon’s speed after 17.0 s
32. Two forces act on a 16-kg object. The first force has a magnitude of 68 N and is directed 24° north of
east. The second force is 32 N, 48° north of west. What is the acceleration of the object resulting from
the action of these two forces?
33. An apple crate with a weight of 225 N accelerates along a frictionless surface as the crate is pulled with a
force of 14.5 N as shown in the drawing. What is the horizontal acceleration of the crate?
34. Solve page 158 Q#6
35. Solve page 158 Q#7
Applying Newton second law to vertical motion practice problems
36. Determine the weight of these masses:
a. 14 kg
b. 0.43 kg
c. 0.70 kg
37. Calculate the mass of these weights:
a. 98N
b. 0.80N
c. 2554N
38. An economy car has a mass of 800 kg. What is the weight of this car?
39. A small yacht weighs 14 700 N. What is its mass in kilograms?
40. A light rope is used to lift a mass of 10 kg. If the tension in the rope is 120 N,
a. What is the weight of the mass
b.
What is the net force?
c.
What is the upward acceleration of the mass?
41. A lunar landing research vehicle (LLRV) is equipped with two hydrogen peroxide lift rockets capable of providing
2200 N of thrust each. If the weight is 1.14 x 104N,
a. What is the net vertical force?
b.
what is its upward acceleration due to the forces acting on it?
42. A rubber ball weighs 4.9 N. At what rate is the ball accelerated straight up if a 69 –N force is applied to it in that
direction?
43. What applied force accelerates a stone that weighs200 N straight up at 10.0 m/s2?
44. A small rocket has a mass of 1.49 kg. The rocket is fired from a high platform but its engine fails to burn properly.
The rocket gains a total upward force of only 10.2 N. At what rate and in what direction is the acceleration?
45. A force of 90 N is excreted straight up on a stone that weighs 7.35 N. Calculate
a. The net force acting on the stone
b. The acceleration of the stone.
46. A rocket which weighs 7840 N on Earth is fired. The force of propulsion is 10440 N. Determine
a. The upward acceleration of the rocket
b. The velocity of the rocket at the end of 10 s
47. A string can withstand a tension of 70 N before breaking. If this string is used to support a 4.0 kg mass t, what is
the maximum upward acceleration that can be given to mass?
48. Calculate the force needed to accelerate an object with mass of 2.0 kg upward at 5.6 m/s2?
49. A person throws a ball that weighs 12 N upward with a force of 20 N. What is its acceleration?
50. A person and an elevator have a combined mass of 5.5 x 103 kg. The elevator’s cable exerts a force of 6.1 x 103N
[up] on the elevator. Find the acceleration of the person and the elevator.
51. Solve page 152 Q#1
52. Solve page 152 Q#2
53. Solve page 153 Q#1
54. Solve page 158 Q#5