College Physics Midterm

A piece of rope is pulled by two people in a tug-of-war. Each pulls with 400N of force. What is the tension in the rope? a) 400N b) 800N c) zero d) 600N

a) 400N

The mass of a typical adult woman is closet to a) 35 kg b) 150 kg c) 75 kg d) 20 kg

c) 75 kg

Convert 1.2 × 10^-3 to decimal notation.

0.0012

The newton is a unit of a) inertia b) density c) force d) mass

c) force

What is the product of 11.24 and 1.95 written with the correct number of significant figures?

21.9

In addition to 1 m= 39.37 in. the following. exact conversion equivalents are given 1 mile = 5180 ft, 1 ft = 12 in, 1 hour = 60 min, and 1 min = 60 s. If a particle has a velocity of 84 miles per hour, its velocity, in m/s is closet to:

3.8 in/s

Two objects of unequal masses, M and m (M > m), are connected by a very light cord passing over an ideal pulley of negligible mass. When released, the system accelerates, and friction is negligible. Which one of the following free-body diagrams most realistically represents the forces acting on the two objects in the moving system?

A

A skydiver, who weighs 500 N, reaches terminal velocity of 90 km/h. The air resistance on the diver is then a) 250N b) 90N c) 500N d) 410N

c) 500N

A rock is thrown vertically into the air. At the top of its path, its acceleration in meters per second per second is a) 9.8 b) greater than 9.8 c) zero d) between 0 and 9.8

a) 9.8

A rock weighs 30N on Earth. A second rocks 30N on the moon. Which of the two rocks has the greater mass? a) The one on the moon b) The one on Earth c) They have the same mass d) Not enough information to say

a) The one on the moon

An object is moving with constant non-zero velocity in the +x direction. The velocity versus time graph of this object is a) a horizontal straight line b) a vertical straight line c) a straight line making an angle with the time axis d) a parabolic curve

a) a horizontal straight line

The slope of a velocity versus time graph gives a) acceleration b) velocity c) displacement d) the distance traveled

a) acceleration

Which of the following graphs represent an object at rest?

a) graph a

For an action force, there must be a reaction force that a) is exactly equal in magnitude b) always acts in the same direction c) is slightly smaller I magnitude than the action force d) is slightly larger in amplitude than the action force

a) is exactly equal in magnitude

An object moving in the +x direction experiences an acceleration of +2.0 m/s^2. This means that the object a) is increasing its velocity by 2.0 m every second b) is traveling at 2.0 m/s c) travels 2.0 m in every seconds d) is decreasing its velocity by 2.0 m/s every second

a) is increasing its velocity by 2.0 m every second

A kilogram is a measure of an object's a) mass b) size c) force d) weight

a) mass

If the velocity versus time graph of an object is a horizontal line, the object is a) moving with zero acceleration b) moving with constant non-zero acceleration c) at rest d) moving with increasing speed

a) moving with zero acceleration

Suppose that a car traveling to the west begins to slow down as it approaches a traffic light. Which of the following statements concerning its acceleration is correct? a) Since the car is slowing down, its acceleration must be negative. b) The acceleration is toward the east. c) the acceleration is zero. d) the acceleration is toward the west.

a) since the car is slowing down, its acceleration must be negative.

The current definition of the standard meter of length is based on. a) the distance traveled by light in a vacuum. b) the distance between the earth and the sun. c)the length of a particular object kept in France. d) the distance between the earth's equator and north pole.

a) the distance traveled by light in a vacuum.

Your weight is a) the gravitational attraction force between you and the Earth b) equal to your mass c) a property of mechanical equilibrium d) all of these

a) the gravitational attraction force between you and the Earth

The attraction of a person's body toward Earth is called weight. The reaction to this force is a) the person's body pulling on Earth b) the person's body pushing against Earth's surface c) the Earth's surface pushing against the person's body d) none of these

a) the person's body pulling on Earth

The motions of a car and a truck along a straight road are represented by the velocity-time graphs in the figure. The two vehicles are initially alongside each other at time t=0. At time T, what is true of the distances traveled by the vehicles since time t=0? a) the truck will have traveled further than the car b) the truck will not have moved c) they will have traveled the same distance d) The car will have traveled further than the truck

a) the truck will have traveled further than the car. (Velocity x Time = displacement) (Truck = area of the square, car = area of the triangle; the area of the square is larger)

If the velocity of an object is zero, then that object cannot be acceleration a) true b) false

a) true

An object is propelled along a straight-line path by a force. If the net force were doubled, the object's acceleration would be a) twice as much b) half as much c) the same d) four times as much

a) twice as much

An airplane increases its speed at the average rate of 15 m/s^2. How much time does its take to increase its speed from 100m/s to 160 m/s. a) 17 s b) 4.0 s c) 0.25 s d) 0.058 s

b) 4.0s

An object covers a distance of 8 meters in the first second of travel, another 8 meters during the next second, and 8 meters again during the third second. Its acceleration in meters per second per second is approximately. a) 8 b) 0 c) 24 d) 5

b) 0

An apple weights 1N. When held at rest above you heard, the net force applied on the apple is a) 1N b) 0N c) 9.8N d) 0.1N

b) 0N

If a freely falling object were somehow equipped with a speedometer, its speed reading would increase each second by about a) 5 m/s b) 10 m/s c) a variable amount d) 15 m/s

b) 10 m/s

A car increases its forward velocity uniformly from 40 m/s to 80 m/s while traveling a distance of 200m. What is its acceleration during this time? a) 8.0 m/s^2 b) 12 m/s^2 c) 24 m/s^2 d) 9.6 m/s^2

b) 12 m/s^2

A har has a mass of 1000kg and accelerates at 2 meters per second. What is the magnitude of the net force exerted on the car? a) 1000N b) 2000N c) 1500N d) 500N

b) 2000N

Which of the following quantities has units of displacement? (There could be more than one correct choice.) a) -120 m/s b) 40 km southwest c) 9.8 m/s^2 d) 32 ft/s^2 vertically downward

b) 40 km southwest

A bullet shot straight up returns to its tarting point in 10s. What is the initial speed of the bullet, assuming negligible air resistance? a) 9.8 m/s b) 49 m/s c) 25 m/s d) 98 m/s

b) 49 m/s

A net force of 125 N is applied to a certain object, As a result, the object accelerates with acceleration of 24.0 m/s^2. The mass of the object is a) 2880 kg b) 5.21 kg c) 144 kg d) 0.200 kg

b) 5.21 kg

Which of the following quantities has units of velocity? a) 9.8 m/s southwest b) 9.8 m/s^2 downward c) 40 km southwest d) 186,000

b) 9.8 m/s southwest

If the acceleration of an object is zero, then that object cannot be moving a) True b) False

b) False

You will have to drive 6.0km at 50 km/hr then another 6.0km at 90km/h. Your average speed over the 12 km drive will be.

b) Less than 70 km/h (You travel longer in the first period b/c its a larger period of time)

If the acceleration of an object is zero, then that object cannot be moving. a) True b) False

b) false

In order to get an object moving, you must push harder on it than it pushed back on you. a) true b) false

b) false

When a ball is thrown straight up with no air resistance, the acceleration at its highest point. a) is upward b) is downward c) reverses from upward to downward d) is zero

b) is downward (gravity never stops, acceleration = gravity)

Suppose that a car traveling to the west (-x direction) begins to slow down as it approaches a traffic light. Which of the following statements about its acceleration is correct? a) Its acceleration is zero b) its acceleration is positive c) its acceleration is negative d) Its acceleration is decreasing in magnitude as the car slows down.

b) its accelerations positive

A force is a vector quantity because it has both a) mass and acceleration b) magnitude and direction c) action and reaction counterparts

b) magnitude and direction

Whenever the net force on an object is zero, its acceleration a) may be more than zero b) may be less than zero c) is zero

b) may be less than zero

If you pound a feather with a hammer, which one feels a greater force? a) always the feather b) the size of the force is always exactly the same on both of them c) if the feather moves, then it felt the greater force. Otherwise the force was the same on both d) always the hammer

b) the size of the force is always exactly the same on both of them

From the edge of a roof top you toss a green ball upwards with initial speed v0 and a blue ball downwards with the same initial speed. Air resistance is negligible. When they reach the ground below a) the green ball will be moving faster than the blue ball. b) the two balls will have the same speed. c) the blue ball will be moving faster than the green ball.

b) the two balls will have the same speed.

While an object near the Earth's surface is in free fall, its a) mass increases b) velocity increases c) mass decreases d) acceleration increases

b) velocity increases

A 10N falling object encounters 10N of air resistance. The net force on the object is. a) 6N b) 10N c) 0N d) 4N

c) 0N

The force of friction on a sliding object is 10 N. The applied force needed to maintain a constant velocity is a) less than 10 N b) More than 10 N c) 10 N

c) 10 N

A car accelerates from rest for 5 seconds until it reaches a speed of 20 m/s. What is the car's acceleration in meters per second per second? a) 3 b) 2 c) 4 d) 1

c) 4

A child standing on a bridge throws a rock straight down. The rick leaves the child's hand at time t=0s. If we take upward as the positive direction, which of the graphs shown below best represents the velocity of the stone as a function of time.

c

Which of the following situation is impossible? a) An object has a velocity directed east and acceleration directed east. b) An object has velocity directed east and acceleration directed west. c) an object has constant non-zero velocity and changing acceleration. d) An object has zero velocity but non-zero acceleration.

c) an object has constant non-zero velocity and chaining acceleration.

If the position versus time graph of an object is a horizontal line, the object is a) moving with constant non-zero speed b) moving with constant non-zero acceleration c) at rest d) moving with increasing speed

c) at rest

An auto manufacture advertises that their car can go from zero to sixty in eight seconds." This is a description of what characteristic of the car's motion? a) Average speed b) instantaneous acceleration c) average acceleration d) instantaneous speed

c) average acceleration

Arnold Strongman and Suzie Small each pull very hard on opposite ends of a massless rope in a tug-of-war. The greater force on the rope is exerted by a) Arnold, of course b) Suzie, surprisingly c) both the same, interestingly enough

c) both the same, interestingly enough

If an object moves with constant acceleration, its velocity must a) always decrease b) change by varying amounts depending on its speed c) change by the same amount each second d) be constant also

c) change by the same amount each second

A heavy block at rest is suspended by a vertical rope. When the block accelerates upward by the rope, the rope tension a) remains the same b) increases c) decreases

c) decreases

A ball tossed vertically upward rises, reaches its highest point, and then falls back to its starting point. During this time the acceleration of the ball is always a) opposite its velocity b) directed upward c) directed downward d) in the direction of motion

c) directed downward

When a bell is thrown straight up with no air resistance, the acceleration at its highest point a) reverses from upward to downward b) is zero c) is downward d) is upward

c) is downward

The current definition of the standard second of time is based on. a) the earth's rotation rate. b) the duration of one year. c) the frequency of radiation emitted by cesium atoms. d) the oscillation of a particular pendulum kept in France.

c) the frequency of radiation emitted by cesium atoms.

When a rock thrown straight upwards gets to the exact top of its path, its a) velocity is about 10 m/s and its acceleration is zero b) velocity is about 10 m/s and its acceleration is about 10 meters per second per second c) velocity is zero and its acceleration is about 10 meters per second per second d) none of these

c) velocity is zero and its acceleration is about 10 meters per second per second.

When a falling object has reached its terminal velocity, its acceleration is a) constant b) g c) zero

c) zero

If a net force accelerates a 4.5kg tool at 40m/s^2, what acceleration would that same net force give to an 18kg tool. a) 180 m/s^2 b) 32 m/s^2 c) 160 m/s^2 d) 10 m/s^2

d) 10 m/s^2

A car accelerates at 2 meters per second per second. Assuming the car starts from rest, how much time does it need to accelerate to a speed of 30 m/s? a) 30 seconds b) 60 seconds c) 2 seconds d) 15 seconds

d) 15 seconds

A 10 N falling object encounters 4N of air resistance. The net force on the object is a) 0 N b) 4 N c) 10 N d) 6 N

d) 6 N

A motorist travels for 3.0 h at 80 km/h and 2.0h at 100 km/h. What is her average speed for the trip? a) 92 km/h b) 85 km/h c) 90 km/h d) 88 km/h

d) 88 km/h

An object's weight may properly be expressed in units of a) Meters b) Cubic centimeters c) Kilograms d) Newtons

d) Newtons

Two boxes are connected to each other by a string as shown in the figure. The 10-N box slides without friction on the horizontal table surface. The pulley is ideal and the string has negligible mass. What is true about the tension T in the string? a) T = 30N b) T = 20N c) T>30N d) T<30N

d) T<30N

A rock from a volcanic eruption is launched straight up into the air with no appreciable air resistance. Which one of the following statements about this rock while it is in the air is correct? a) On the way down, both its velocity and acceleration are downward, and at the highest point both its velocity and acceleration are zero. b) The acceleration is downward at all points in the motion except that is zero at the highest point. c) Throughout the motion, the acceleration is downward, and the velocity is always in the same direction as the acceleration. d) The acceleration is downward at all points in the motion.

d) The acceleration is downward at all points in the motion.

A skydiver of mass 100kg experiences air resistance of 500N, and an acceleration of a) about 0.3g b) about 0.2g c) more than 0.5g d) about 0.5g

d) about 0.5g

The slope of a velocity versus time graph gives a) displacement b) the distance traveled c) velocity d) acceleration

d) acceleration

In the figure, what does the spring scale read? The pulleys are ideal and the strings and scale are also massless. a) Exactly 2.0 N b) 0.00 N c) 0.50 N d) exactly 1.0N

d) exactly 1.0N

If an object falling freely were to somehow be equipped with an odometer to measure the distance it travels, then the amount of distance it travels each succeeding second would be a) less and less each second b) constant c) doubled d) greater than the second before

d) greater than the second before

Compared to the mass of a certain object on Earth, the mass of the same object o the moon is a) one sixth as much b) six times as much c) zero d) the same

d) the same

The slope of a position versus time graph gives a) displacement b) the distance traveled c) acceleration d) velocity

d) velocity