AP Physics Ch. 1-8 (2019 AP Physics Midterm)
A plane is flying due South (180 degrees) at 500 km/h. A wind blows from East to West (270 degrees) at 45.0 km/h. Find the plane's velocity with respect to the ground.
502 km/h at 185 degrees
Starting from city A, a car drives 250 miles east to city B, then 300 miles north to city C, and finally 700 miles west to city D. What is the distance between city A and city D? (Assume that each measured value has two significant figures.)
540 mi
A polar bear starts at the North Pole. It travels 1.0 km south, then 1.0 km east, and then 1.0 km north to return to its starting point. This trip takes 30 min. What was the bear's average speed?
6.0 km/h
A motorist travels 160 km at 80 km/h and 160 km at 100 km/h. What is the average speed of the motorist for this trip?
89 km/h
A stone is thrown horizontally with an initial speed of 10 m/s from the edge of a cliff. A stop watch measures the stone's trajectory time from the top of the cliff to the bottom to be 4.3 s. What is the height of the cliff?
91 m
What is the difference, in meters, between 103.5 m and 102.24 m?
1.3
The coefficients of static and kinetic frictions for plastic on wood are 0.50 and 0.40, respectively. How much horizontal force would you need to apply to a 3.0 N plastic calculator to start it moving from rest?
1.5 N
A boat, whose speed is still in 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?
10 m/s
Two vectors A and B have components (0,1) and (-1,3), respectively. What are the components of the sum of these two vectors?
(-1,4)
In the graph shown, what is the velocity at t=4.0 s?
0
A wooden block slides directly down an inclined plane, at a constant velocity of 6.0 m/s. What is the coefficient of kinetic friction, if the plane makes an angle of 25 degrees with the horizontal?
0.47
An object is on a frictionless inclined plane. The plane is inclined at an angle of 30 degrees with the horizontal. What is the object's acceleration?
0.50 g
A point on a wheel rotating at 5.00 rev/s is located 0.200 m from the axis. What is the centripetal acceleration?
198 m/s^2
The average life of an animal is 70 years. Assume one numerical figure, write this in power of ten in seconds.
2 x 10^9 s
What, approximately, is the percent uncertainty for the measurement 5.2?
2%
Express the following sum with the correct number of significant figures: 1.00 kg + 1531 g + 2.54 x 10^4 mg
2.56 kg
An average human has a heart rate of 70 beats per minute. If someone's heart beats at that average rate over a 70-yr lifetime, how many times would it beat?
2.6 x 10^9
A girl throws a rock horizontally, with a velocity of 10 m/s, from a bridge. It falls 20 m to the water below. How far does the rock travel horizontally before striking the water?
20 m
If a ball is thrown with a velocity of 25 m/s at an angle of 37 degrees above the horizontal, what is the horizontal component of the velocity?
20 m/s
How many m/s is 50 mi/h equivalent to? (1 mi = 1609 m.)
22 m/s
A fighter plane moving 200 m/s horizontally fires a projectile with speed 50.0 m/s in a forward direction of 30.0 degrees below the horizontal. What is the speed of the projectile with respect to a stationary observer on the ground?
245 m/s
A car starts from rest and accelerates uniformly at 3.0 m/s^2. A second car starts from rest 6.0 s later at the same pint and accelerates uniformly at 5.0 m/s^2. How long does it take the second car to overtake the first car?
27 s
An airplane travels at 300 mi/h south for 2.00 h and then at 250 mi/h north for 750 miles. What is the average speed for the trip?
270 mi/h
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/s^2?
284 N
What is the volume, and its approximate uncertainty, of a sphere of radius 1.96 +/- 0.01 m?
31.5 +/- 0.5 m^3
A projectile is launched with an initial velocity of 60.0 m/s at an angle of 30.0 degrees above the horizontal. How far does it travel?
318 m
A rope one-meter long rests on a table where the coefficient of friction is 0.50. What maximum length of rope can hang over the side before the whole rope will slip off?
33 cm
A 400-m tall tower casts a 600-m long shadow over a level ground. At what angle is the sun elevated above the horizon?
34 degrees
How many significant figures does the number 15.00 g have?
4
An object moves with a constant speed of 20.0 m/s on a circular track of radius 100.0 m. What is the acceleration of the object?
4.0 m/s^2
An airplane increases its speed from 100 m/s to 160 m/s, at the average rate of 15 m/s^2. How much time does it take for the complete increase in speed?
4.0 s
What is the result, of 1.58 cm/0.379 3 cm?
4.17
A rectangle 3.25 m long and 1.5 m wide. What is its area?
4.9 m^2
A jet fighter plane is launched from a catapult on an aircraft carrier. It reaches a speed of 42 m/s at the end of the catapult, and this requires 2.0 s. Assuming the acceleration is constant, what is the length of the catapult?
42 m
The maximum speed around a level curve is 30.0 km/h. What is the maximum speed around a curve with twice the radius? (Assume all other factors remain unchanged.)
42.4 km/h
A car traveling 30 m/s is able to stop in a distance d. Assuming the same braking force, what distance does this car require to stop when it is traveling twice as fast?
4d
Vector A=(1,3). Vector B=(3,0). Vector C=A+B. What is the magnitude of C?
5
Sue and Sean are having a tug-of-war by pulling on opposite ends of a 5.0-kg rope. Sue pulls with a 15-N force. What is Sean's force if the rope accelerates toward Sue at 2.0 m/s^2?
5.0 N
The radius of the Earth is 3 963 mi. What is the surface area of the Earth in square meters? (1 mi = 1 609 m.)
5.1 x 10^14 m^2
What is the percent uncertainty in the measurement 2.58 +/- 0.15 cm?
5.8%
A ly (light year) is the distance that light travels in one year. The speed of light is 3.00 x 10^8 m/s. How many miles are there in a ly? (1 mi=1609 m, 1 year=365 days)
5.88x10^12
If you are driving 90 km/h along a straight road and you look to the side for 3.0 s, how far do you travel during this inattentive period?
75 m
A ball thrown horizontally from a point 24 m above the ground, strikes the ground after traveling horizontally a distance of 18 m. With what speed was it thrown?
8.1 m/s
A bullet is fired horizontally, and at the same instant a second bullet is dropped from the same height. Ignore air resistance. Compare the times of fall of the two bullets.
The hit the ground at the same time
A stone is thrown straight up. At the top of its path, the net force acting on it is
equal to its weight
Objects A and B both start from rest. They both accelerate at the same rate. However, object A accelerates for twice the time as object B. What is the distance traveled by object A compared to that of object B?
four times as far
You are throwing ball for the second time. If the ball leaves your hand with twice the velocity it had on your first throw, its horizontal range R (compared to your first serve) would be
four times as much
If two vectors originally point in the same direction, the resultant is the smallest when the angle between them
is 180 degrees
Which of the following has three significant figures?
0.050 0 mm
Determine the number of significant figures in the number 100.01 m.
1.260
If you blow up a balloon, and then release it, the balloon will fly away. This is an illustration of
Newton's Third Law
Two objects are thrown from the top of a tall building. One is thrown up, and the other is thrown down, both with the same initial speed. What are their speeds when they hit the street?
They are traveling at the same speed
Can an object's velocity change direction when its acceleration is constant?
Yes, this is possible, and a rock thrown straight up is an example.
Its more difficult to start moving a heavy carton from rest than it is to keep pushing it with constant velocity, because
coefficient of kinetic friction < coefficient of static friction
If the acceleration of an object is always directed perpendicular to its velocity,
the object is turning
The number of significant figures in 0.40 cm is
two
Write out the number 5.92 x 10^-5 in full with a decimal point and correct number of zeros.
0.0000592
A swimmer heading directly across a river 200 m wide reaches the opposite bank in 6 minutes 40 seconds. She is swept downstream 480 m. How fast can she swim in still water?
0.50 m/s
A jumper in the long-jump goes into the jump with a speed of 12 m/s at an angle of 20 degrees above the horizontal. How long is the jumper in the air before returning to the Earth?
0.84 s
The acceleration of gravity on the mood is only one-sixth of that on earth. If you hit a baseball on the moon with the same effort (and at the speed and angle) that you would on earth, the ball would land
6 times as far
A block of mass M slides down a frictionless plane inclined at an angle (theta) with the horizontal. The normal reaction force exerted by the plane on the block is
Mgcos(theta)
A packing crate slides down an inclined ramp at constant velocity. thus we can deduce that
a frictional force is acting on it
An object is moving with constant non-zero acceleration in the +x axis. The position versus time graph of this object is
a parabolic curve
A net force F acts on a mass m and produces an acceleration a. What acceleration results if a net force 2F acts on mass 4m?
a/2
The slope of a velocity versus time graph gives
acceleration
Action-reaction forces
always act on different objects
If you exert a force F on an object, the force which the object exerts on you will
always be F
Human reaction time is usually greater than 0.10 s. If your friend holds a ruler between your fingers and releases it without warning, how far can you expect the ruler to fall before you catch it?
at least 4.9 cm
A constant net force acts on an object. Describe the motion of the object.
constant acceleration
Two displacement vectors have magnitudes of 5.0 m and 7.0 m, respectively. When these two vectors are added, the magnitude of the sum
could be as small as 2.0 m, or as large as 12 m
If you push a 4.0-kg mass with the same force that you push a 10 kg-mass from rest,
the 4.0-kg mass accelerates 2.5 times faster than the 10-kg mass
A brick and a feather fall to the earth at their respective terminal velocities. Which object experiences the greater force of air friction?
the brick
A stone is thrown horizontally from the top of a tower at the same instant a ball is dropped vertically. Which object is traveling faster when it hits the level ground below?
the stone
A child's toy is suspended from the ceiling by means of a string. The earth pulls downward on the toy with a weight force of 8.0 N. If this is the "action force," what is the "reaction force"?
the toy pulling upward on the earth with an 8.0 N force
The number of forces acting on a car parked on a hill (with parking brakes engaged) is
three
Objects A and B both start at rest. They both accelerate at the same rate. However, object A accelerates for twice the time as object B. What is the final speed of object A compared to that of object B?
twice as fast
The area under a curve in an acceleration versus time graph gives
velocity
You are standing in a moving bus, facing forward, and you suddenly fall backward. You can imply from this that the bus's
velocity increased
All of the following are base units of the SI system except:
volt
If you run a complete loop around and outdoor track (400 m), in 100 s, your average velocity is
zero
When you sit on a chair, the resultant force on you is
zero
An object starts from rest and undergoes uniform acceleration. During the first second it travels 5.0 m. How far will it move during the first second?
15 m
A car is negotiating a flat curve of radius 50 m with a speed of 20 m/s. The centripetal force provided by friction is 1.2 x 10^4 N. What is the mass of the car?
1500 kg
A person stands 35.0 m from a flagpole. With a protractor at eye level, he finds that the angle at the top of the flagpole makes with the horizontal is 25.0 degrees. How high is the flagpole? (The distance from his feet to his eyes is 1.7 m.)
18.0 m
If you walk 6.0 km in a straight line in a direction north of east and you end up 2.0 km north and several kilometers east. How many degrees north of east have you walked?
19 degrees
A horizontal force of 5.0 N accelerates a 4.0-kg mass, from rest, at a rate of 0.50 m/s^2 in the positive direction. What friction force acts on the mass?
3.0 N
Write the number 0.000 34 in power of ten notation.
3.4 x 10^-4
A boat can move at 30 km/h in still water. How long will it take to move 12 km upstream in a river flowing 6.0 km/h?
30 min
Which of the following is an example of a scalar quantity?
speed
The force that keeps you from sliding on an icy sidewalk is
static friction
Which of the following is an accurate statement?
A vector cannot have zero magnitude if one of its components is not zero.
A roller coaster car is on a track that forms a circular loop in the vertical plane. If the car is to just maintain contact with track at the top of the loop, what is the minimum value for its centripetal acceleration at this point?
G downward
Who has a greater weight to mass ratio, a person weighing 400 N or a person weighing 600 N?
neither; their ratios are the same
A pilot drops a bomb from a plane flying horizontally. When the bomb hits the ground, the horizontal location of the plane will
be over the bomb
Two toy cars (16 kg and 2.0 kg) are released simultaneously on an inclined plane that makes an angle of 30 degrees with the horizontal. Which statement best describes their acceleration after being released?
both cars accelerate at the same rate
A n object, of mass M, is suspended by a string from the ceiling inside an elevator. The elevator is traveling upward with a constant speed. The tension in the string is
equal to Mg
A package of supplies is dropped from a plane, and one second later a second package is dropped. Neglecting air resistance, the distance between the falling packages will
increase
Ball A is dropped from the top of a building. One second later, ball B is dropped from the same building. As time progresses, the time between them
increases
A skydiver jumps from a high-flying plane. When she reaches terminal velocity, her acceleration
is essentially zero
A ball is thrown straight up. When the ball reaches the highest point
its velocity is zero and its acceleration is not zero