Physical Science Chapter 12 Forces
If you are given the mass of an object in pounds, the time in seconds, and the distance in feet, what must you do before you can calculate the momentum in SI units? A) convert the mass to kilograms B) convert the distance to meters C) both a and b D) None of the above
C) both a and b
Of the following, the greatest gravitational force would occur between A) a marble and a baseball 5 meters apart B) a loaded freighter on the high seas and Earth C) the moon and an astronaut sanding on the moon D) the moon and Earth
D) the moon and Earth
The SI unit of force, named after the scientist who described the relationship between motion and force, is called a) newton b) einstein c) curie d) pasteur
a ) newton
One pound is equal to how many newtons? a) 4.448N b) 2.2N c) 0.225N d) 12.5N
a) 4.448N
Which of the following will result in the greatest acceleration? a) 56 N acting on a 1-kg box b) 56N acting on a 2-kg box c) 23 N acting on a 2-kg box d) 23 N acting on a 5 kg box
a) 56 N acting on a 1-kg box
Which statement about weight is incorrect? a) An object weighs more on the moon than it weighs on Earth. b) A change in an object's location can change the object's weight. c) An object's weight is directly proportional to its mass. d) The weight of an object depends on gravity.
a) An object weighs more on the moon than it weighs on Earth.
How does the total momentum of two objects before a collision compare with the total momentum after the collision? a) It is the same b) It is less c) It is equal to zero d) It is greater
a) It is the same
The law that states that every object maintains constant velocity unless acted on by and unbalanced force is a) Newton's first law of motion b) Newton's second law of motion c) Newton's third law of motion d) the law of conservation of momentum
a) Newton's first law of motion
Which statement about action-reaction force pairs is incorrect? a) They act on the same object. b) They always occur in pairs. c) They occur at the same time. d) They are equal and opposite.
a) They act on the same object.
Which of the following has a momentum of zero? a) a newspaper lying on a table b) a plane flying through the air c) a leaf falling to the ground d) All of the about
a) a newspaper lying on a table
What happens immediately after a sky diver opens her parachute? a) air resistance greatly increases b) the sky diver is in free fall c) the sky diver's speed greatly increases d) the force of gravity greatly increases
a) air resistance greatly increases
When the velocity of an object changes, it is acted upon by a(n) a) force b) inertia c) momentum d) deceleration
a) force
When an object is in free fall, the only force acting on it is a) gravity b) friction c) inertia d) terminal velocity
a) gravity
The tendency of an object at rest to remain at rest is a) inertia b) momentum c) free fall d) acceleration
a) inertia
If you divide momentum by velocity, the result is the value of the object's a) mass b) direction c) energy d) speed
a) mass
What is the unbalanced force that slows down a ball rolling across the floor? a) the force of friction b) the force of gravity c) the force of inertia d) the force of momentum
a) the force of friction
If two objects with different masses and traveling with different velocities collide, what law allows you to predict the motion of the objects after the collision? a) the law of conservation of momentum b) the law of universal gravitation c) Newton's third law d) Newton's second law
a) the law of conservation of momentum
If an equal force is applied to two cars of equal mass, Car A and Car B, Car A will have _____ acceleration as (than) Car B. a) the same b) greater c) less d) the opposite
a) the same
Which of the following equations is correct? a) w=mg b) w=m/g c) w=g/m d) w=g+m
a) w=mg
What is the momentum of a 255 g apple falling at 16.0m/s? a) 4.08m/s^2 downward b) 4.08kg x m/s downward c) 15.9 m/s^2 downward d) 15.9 kg x m/s downward
b) 4.08 kg x m/s downward
Calculate the velocity of a 90.5 kg man running south with a momentum of 389 kg • m/s. a) .233 m/s south b) 4.30 m/s south c) 23.3 m/s south d) 35.2 m/s south
b) 4.30 m/s south
A 10.0 kg dog chasing a rabbit north at 6.0 m/s has a momentum of a) .6 kg m/s b) 60.0 kg m/s north c) 60.0 m/s d) 60.0 kg/s
b) 60.0 kg m/s north
A force of 240.0 N causes an object to accelerate at 3.2 m/s^2. What is the mass of the object? a) .0013kg b) 75 kg c) 240 kg d) 768kg
b) 75 kg
The law that states that the unbalanced force acting on an object equals the object's mass times its acceleration is a) Newton's first law of motion b) Newton's second law of motion c) Newton's third law of motion d) the law of conservation of momentum
b) Newton's second law of motion
Which object has the greatest inertia? a) a tennis ball b) a bowling ball c) a beach ball d) a volleyball
b) a bowling ball
Which is an example of projectile motion? a) a rolling bowling ball b) a dart thrown at a dart board c) a balloon rising in the air d) a high-speed train accelerating
b) a dart thrown at a dart board
The gravitational force between two objects depends on masses of objects and a) accelerations of objects b) distance between objects c) speeds of objects d) sizes of objects
b) distance between objects
Orbital motion is a combination of a) mass and friction b) forward motion and free fall c) acceleration and gravity d) weight and vertical velocity
b) forward motion and free fall
Free-fall acceleration near Earth's surface a) depends on an object's weight b) is the same for all objects c) depends on an object's mass d) none of the above
b) is the same for all objects
The force exerted on the racket by a hit tennis ball is the a) gravitational force b) reaction force c) acceleration d) action force
b) reaction force
When air resistance balances the weight of a falling object, the velocity a) slowly decreases b) remains constant c) rapidly increases d) None of the above
b) remains constant
When gravitational forces and air resistance equalize on an object that is falling toward Earth and the object stops accelerating, what is the velocity of an object called? a) resultant velocity b) terminal velocity c) instantaneous velocity d) average velocity
b) terminal velocity
What is the reaction force when you place a cup on a table? a) the force of the cup on the table b) the force of the table on the cup c) the force of gravity on the table d) the force of gravity on the cup
b) the force of the table on the cup
One newton is the force that can give a mass of 1 kg an acceleration of a) 1 m/s b) 9.8 m/s c) 1 m/s2 d) 9.8m/s2
c) 1 m/s2
What unbalanced force is needed to give a 976 kg vehicle an acceleration of 2.50 m/s^2? a) 3.90 x 10^2N b) 3.90 x 10^2lb c) 2.44 x 10^3 N d) 2.44 x 10^3 lb
c) 2.44 x 10^3N
Earth pulls on the moon and holds the moon in its orbit. The moon pulls on Earth with an equal and opposite force. This is an example of a) Newton's first law b) Newton's second law c) Newton's third law d) None of the about
c) Newton's third law
The law that states for every action force there is an equal and opposite reaction force is a) Newton's first law of motion b) Newton's second law of motion c) Newton's third law of motion d) the law of conservation of momentum
c) Newton's third law of motion
A force is continuously applied to an object, causing it to accelerate. After a period of time, however, the object stops accelerating. What conclusions can be drawn? a) The mass of the object has increased. b) Gravity on the object has increased. c) The object is experiencing some kind of friction. d) The momentum of the object has reached a maximum.
c) The object is experiencing some kind of friction.
Which object does not have momentum? a) a fishing swimming in a pond b) a feather falling to the ground c) a rock by the side of the road d) a boulder rolling down a hill
c) a rock by the side of the road
Which of the following is not a factor in calculating momentum? a) mass b) direction c) acceleration d) speed
c) acceleration
If the net force on an object is zero then the object has a) reaction forces b) action forces c) balanced forces d) unbalanced forces
c) balanced forces
When objects are moved further apart from each other, the force of gravity between them a) increases b) stays the same c) decreases d) decreases at first that increases
c) decreases
Whenever a force is exerted, another force occurs that is _____ in size, and _____ in direction. a) equal, same b) smaller, same c) equal, opposite d) smaller, opposite
c) equal, opposite
What force causes a skater sliding on the ice to gradually slow down? a) a balanced force b) inertia c) friction d) acceleration
c) friction
Astronauts "float" when inside an orbiting spaceship because they are a) weightless b) in a vacuum c) in free fall d) outside Earth's gravity
c) in free fall
When a moving bowling ball hits a pin, some of the ball's momentum a) doubles in force b) increases the pin's mass c) is transferred to the pin d) is lost
c) is transferred to the pin
Which of the following units is used to measure acceleration? a) m/s b) m s c) m/s ^2 d) m^2/s^2
c) m/s ^2
Increasing which of these conditions results in more gravitational force between two objects? a) distance b) acceleration c) mass d) surface area
c) mass
Weight is best described as a) an object's resistance to acceleration b) what causes an object to fall c) the downward force exerted on an object due to gravity d) a force solely dependent on an object's mass
c) the downward force exerted on an object due to gravity
An object's momentum is determined by the object's a. Weight and velocity b. mass and acceleration c. mass and velocity d. weight and acceleration
c. mass and velocity
Which of the following is true? a) Weight and mass are proportional but not equal. b)Weight is gravitational force an object experiences due to its mass c) The weight of an object on Earth is greater than the weight of the same object on the moon, but the object's mass stays the same d) All of the above
d ) All of the above
Express the following as an equation: One newton is the force that can give an object with a mass of 1 kg an acceleration of 1 m/s2. a) 1 N= 1kg /1 m/s2 b) 1 N x 1 kg= 1m/s2 c) 1 N= 1 m/s2/ 1kg d) 1N = 1kg x 1 m/s2
d) 1N = 1kg x 1 m/s2
What is the approximate terminal velocity of a sky diver before the parachute opens? a) 32mi/h b) 32km/h c) 320 mi/h d) 320 km/h
d) 320 km/h
A .25 kg steel ball experiences a net force of 1.15 N as it rolls down a ramp. What is the acceleration of the ball? a) .29m/s^2 b) .90m/s ^2 c) 1.4m/s^2 d) 4.6m/s^2
d) 4.6 m/s^2
How much does a 59.0 kg woman weigh on Earth? a. 6.02 N b. 59.0 lb c. 145 lb d. 578 N
d) 578N
Two identical cars are traveling at equal speeds. One is going north and the other south. If they collide head-on and stick together, what will happen to the motion of the cars? a) Both cars will move north b) Both cars will move east c) Both cars will move south d) Both cars will stop
d) Both cars will stop
Near Earth's surface, the strongest gravitational force would occur between an elephant and a) the sun b) the moon c) a cat d) Earth
d) Earth
Near Earth's surface, an object's free-fall acceleration increases as its a) mass increases b) weight increases c) speed increases d) None of the above
d) None of the above
Which statement illustrates Newton's first law? a) a stone will not move unless something pushes or pulls it b) a ball rolling across the floor eventually slows down c) as a car comes to a stop, the passengers continue to move forward d) all of the about
d) all of the about
Whenever an object is standing still, which value is always zero? a) speed b) velocity c) momentum d) all of the above
d) all of the above
Which of the following objects exert a gravitational force? a) a bowling bowl b) a book c) a feather d) all of the above
d) all of the above
The weight of an object can be calculated by multiplying mass by a) distance b) speed c) velocity d) free-fall acceleration
d) free-fall acceleration
In the absence of air resistance, how would the acceleration of a 1.5 kg book and the acceleration of a 15kg rock differ if the objects were dropped from the same height? a) the book would accelerate twice as fast as the rock b) the rock would accelerate twice as fast as the book c) the book would accelerate ten times as fast as the rock d) they would not differ, they would be the same
d) they would not differ, they would be the same
A seat belt helps you when your car stops suddenly by providing a) balanced forward force b) unbalanced forward force c) balanced backward force d) unbalanced backward force
d) unbalanced backward force
A tug-of-war that results in one team pulling the other across the line is an example of a) action force b) reaction forces c) balanced forces d) unbalanced forces
d) unbalanced forces