Download answers - Stevenson High School

1
The slope of the tangent on a position-time graph equals the
Answer
2
The area under the curve on a velocity-time graph equals the:
Answer
3
acceleration
An object moves back and forth, as shown in the position-time graph. At which points is the velocity positive?
Answer
5
displacement from the original position to its position at time t
The graph shows the velocity of each of two bodies as a function of time. Which of the quantities given below must be the same
for both of the bodies?
Answer
4
instantaneous velocity
1,7,8
Use the graph below to determine the displacement of the object at the end of the first seven seconds.
Answer
-4 meters
6
Use the graph below to calculate the velocity of an object during interval C.
Answer
7
Use the graph below to determine which section of the graph represents a time interval when an object at rest.
Answer
8
A
Use the graph below to determine the average velocity of an object during the first six seconds?
Answer
9
4 m/s
-4/6 meters/sec
Use the vector in the diagram below to determine the magnitude and direction of the resultant of x and y:
Answer
10
An object is accelerated from rest at the rate of 3.0 m/s 2. After it has traveled 13.5 m, its velocity is:
Answer
11
The force required to accelerate a mass of 10.00 kg at 4.00 m/s 2 is:
Answer
12
b, d, e
When velocity is positive and acceleration is negative, what happens to the object's motion?
Answer
17
multiply by 1000 and divide by 3600
An object moves along the x axis as shown in the diagram. At which point or points is the object at rest?
Answer
16
10 N
To convert a quantity from km/h to m/s, you must
Answer
15
Moving up at constant acceleration
Forces of 6 N and 8 N act on a frictionless puck with a mass of 3 kg at an angle of 90 0 with each other.What is the magnitude in
Newtons of the net force on the puck?
Answer
14
40.0 N
A man of mass 70 kg stands on platform scales in an elevator. Suppose the scales read 750 N. How is the elevator moving at that
time?
Answer
13
9.0 m/s
The object slows down.
A toy car is given an initial velocity of 5.0 m/s and experiences a constant acceleration of 2.0 m/s 2. What is the final velocity after
6.0 s?
Answer
17 m/s
18
For an object moving along a trajectory, the vertical acceleration of the object ____ as the position changes.
Answer
19
In projectile motion, the rising and falling times of the object are equal if the launching position is ___ the landing position.
Answer
20
being accelerated.
A wagon with a weight of 300.0 N is accelerated across a level surface at 0.5 m/s 2. What net force acts on the wagon? (g = 9.81
m/s2)
Answer
25
upward
If it is known that a net force is acting on an object, then the object is most likely
Answer
24
greater than 1.5 x 10 4 N
If the force of gravity on a balloon is 3000 N, and the lift force provided by the atmosphere is 3300 N, in which direction is the net
force acting?
Answer
23
-9.80 m/s2
Two tugboats have parallel tow lines attached to the same barge. The tugboats are pulling in the same direction, both with a force
of 9 x 103 N. The Net force in the direction of the tow lines is:
Answer
22
at the same height as
Which of the following is a value for the acceleration of objects in free fall?
Answer
21
is constant
15 N
Two students push on a sled. One pushes with a force of 30 Newtons east and the other exerts a force of 40 Newtons south, as
shown in the top-view diagram below. Which vector best represents the resultant of these two forces?
Answer
26
The diagram below represents the relationship between velocity and time of travel for four cars, A, B, C, and D, in straight-line
motion. Which car has the greatest acceleration during the time interval 10. seconds to 15 seconds
Answer
27
A car travels 90 meters due north in 15 seconds. Then the car turns around and travels 40 meters due south in 5.0 seconds. What is
the magnitude of the average velocity of the car during this 20 second interval?
Answer
28
430 m
The displacement-time graph below represents the motion of a cart initially moving forward along a straight line. During which
interval is the cart moving forward at constant speed?
Answer
30
2.5 m/s
An airplane originally at rest on a runway accelerates uniformly at 6.0 m/s 2 for 12 seconds. During this 12 second interval, the
airplane travels a distance of approximately
Answer
29
D
BC
A 4.0 kilogram rock and a 10 kilogram stone fall freely from rest from a height of 1.00 meters. After they fall for 2.0 seconds, the
ratio of the rock's speed to the stone's speed is
Answer
1:1
31
A ball is thrown horizontally with an initial velocity of 20.0 meters per second from the top of a tower 60.0 meters high. What is
the initial vertical velocity of the ball?
Answer
32
A ball is thrown horizontally with an initial velocity of 20.0 meters per second from the top of a tower 60.0 meters high. What is
the approximate total time required for the ball to reach the ground? [Neglect air resistance.]
Answer
33
3.50 s
A ball is thrown horizontally with an initial velocity of 20.0 meters per second from the top of a tower 60.0 meters high. What is
the horizontal velocity of the ball just before it reaches the ground? [Neglect air resistance.]
Answer
34
0 m/s
20.0 m/s
The diagram below shows a 10.0 kilogram mass held at rest on a frictionless 30.0° incline by force F. What is the approximate
magnitude of force F?
Answer
49.1 N
35
The graph below represents the relationship between the forces applied to an object and the corresponding accelerations produced.
What is the inertial mass of the object?
Answer
36
A 2.0 kilogram mass weighs 10 Newtons on planet X. The acceleration due to gravity on planet X is approximately
Answer
37
50 N
If the sum of all the forces acting on a moving object is zero, the object will
Answer
40
accelerating in the direction of F 1
The magnitude of the force that a baseball bat exerts on a ball is 50 Newtons. The magnitude of the force that the ball exerts on the
bat is
Answer
39
5.0 m/s2
In the diagram below, a box is on a frictionless horizontal surface with forces F 1 and F2 acting as shown. if the magnitude of F 1 is
greater than the magnitude of F 2 then the box is
Answer
38
0.50 kg
continue moving with constant velocity
A series of unbalanced forces was applied to each of two blocks, A and B. The graphs below show the relationship between
unbalanced force and acceleration for each block. Compared to the mass of block A, the mass of block B is
Answer
twice as great
41
The diagram below represents a block sliding down an incline. Which vector best represents the frictional force acting on the
block?
Answer
42
The diagram below shows a horizontal 8.0 Newton force applied to a 4.0 kilogram block on a frictionless table. What is the
magnitude of the block’s acceleration?
Answer
43
The toy pulling upward on the Earth with an 8.0-N force.
An object of mass m is hanging by a string from the ceiling of an elevator. The elevator is moving upward, but slowing down.
What is the tension in the string?
Answer
48
a/2. x
A child's toy is suspended from the ceiling by means of a string. The Earth pulls downward on the toy with its weight force of 8.0
N. If this is the "action force," what is the "reaction force"?
Answer
47
zero.
A net force F accelerates a mass m with an acceleration a. If the same net force is applied to mass 2m, then the acceleration will be
Answer
46
the first law
A rocket moves through empty space in a straight line with constant speed. It is far from the gravitational effect of any star or
planet. Under these conditions, the force that must be applied to the rocket in order to sustain its motion is
Answer
45
2.0 m/s2
Which of Newton's laws best explains why motorists should buckle-up?
Answer
44
B
less than mg
Two toy cars (16 kg and 2.0 kg) are released simultaneously on an inclined plane that makes an angle of 30° with the horizontal.
Make a statement which best describes their acceleration after being released.
Answer
Both cars accelerate at the same rate.
49
A sports car of mass 1000 kg can accelerate from rest to 27 m/s in 7.0 s. What is the average forward force on the car?
Answer
50
A person of weight 480 N stands on a scale in an elevator. What will the scale be reading when the elevator is accelerating
downward at 4.00 m/s2?
Answer
51
10.0 m/s
The driver of a motorboat that can move at 10 m/s in still water wishes to travel directly across a river 1.6 km wide in which the
current flows at 5.0 m/s. How long will it take to cross the river?
Answer
57
20 min
A boat, whose speed in still water is 8.0 m/s, is directed across a river with a current of 6.0 m/s. What is the speed of the boat as it
crosses the river?
Answer
56
in a northwesterly direction.
Your motorboat can move at 30 km/h in still water. How much time will it take you to move 12 km downstream, in a river flowing
at 6.0 km/h?
Answer
55
1.3 s
You are trying to cross a river that flows due south with a strong current. You start out in your motorboat on the east bank desiring
to reach the west bank directly west from your starting point. You should head your motorboat
Answer
54
4.9 m/s2
A mass is placed on a smooth inclined plane with an angle of 37° to the horizontal. If the inclined plane is 5.0-m long, how long
does it take for the mass to reach the bottom of the inclined plane after it is released from rest?
Answer
53
284 N
An object is on a frictionless inclined plane. The plane is inclined at an angle of 30° with the horizontal. What is the object's
acceleration?
Answer
52
3.9 x 103 N
2.4 min
A 40kg boy is playing with his 20kg sister who is sitting in a box on the floor. Starting from rest, he pushes the box with a constant
force. What is the direction of the net force?
Answer
58
A 40kg boy is playing with his 20 kg sister who is sitting in a box on the floor. Starting from rest, he pushes the box with a constant
horizontal force of 150 N for 2m and then jumps into the box, which moves at a constant speed for a given time period. What is
the net force during that given time period?
Answer
59
A basketball is dropped from a height of 1.5m above the floor of the gym. After it bounces, it reaches a maximum height of 50 cm.
Which diagram shows the correct arrangement of the observed acceleration at the top of the bounce?
Answer
60
The diagram below shows a block sliding down a plane inclined plane of known length from rest at angle with the horizontal. What
is the formula you can use to calculate the ideal (theoretical) acceleration of the block?
Answer
61
Ag sin θ
The diagram below represents a block sliding down an incline. Which vector best represents the observed acceleration acting on
the block?
Answer
D
62
The diagram below represents a block sliding down an incline. Which vector best represents the acceleration loss due to friction?
Answer
B