Chapter 2 Newton’s Laws of Motion – Formative Quiz – Flashcards
Unlock all answers in this set
Unlock answersquestion
To say there is no such thing as only one force means
answer
there must also be an oppositely directed force.
question
A given net force propels an object along a straight-line path. If the mass were doubled, its acceleration would
answer
be half.
question
A jumbo jet of mass 100,000 kg during takeoff experience a thrust for each of its four engines of 50,000 N, producing an acceleration of
answer
2 m/s^2.
question
Both ends of a piece of rope are pulled by two people in a tug-of-war. If each pulls with a 400-N force, the tension in the rope is
answer
440 N
question
When a 500-N parachutist opens his chute and experiences 800 N of air resistance, the net force on him is
answer
300 N upward
question
You drive your car along the highway at a constant 60 km/h and apply the brakes until the car slows to 40 km/h. If at that moment you suddenly release the brakes, the car tends to
answer
continue moving at 40 km/h.
question
A ball is thrown vertically into the air. Because of air resistance, its time coming down compared with its time going up is
answer
more
question
If you carry a heavy bag of groceries and bang your hand against the wall, the concept that best explains why your hand hurts is
answer
inertia
question
A particle is being accelerated through space by a 10-N force. Suddenly the particle encounters a second force of 10 N in the opposite direction. The particle with both forces acting
answer
continues at the same speed it had before encountering the second force
question
An iron ball and a wooden ball of the same size are dropped from a tall tower. Taking air resistance into consideration, the object to hit the ground first will be the
answer
heavier iron ball
question
Whirl a rock at the end of a string and it follows a circular path. If the string breaks, the rock tends at first to
answer
follow a straight-line path
question
A ball is thrown upward and caught when it returns. When air resistance affects the ball, compared with the initial upward speed, the speed of the ball when caught is
answer
less
question
To steadily (constantly) increase the velocity of something requires a
answer
constant net force
question
A quick jerk on a sheet of paper beneath a box of cereal doesn't topple the box, which best illustrates that
answer
the box has inertia
question
An huge bear and a leaf fall from a tree through the air to the ground below. The force of air resistance is greater on the
answer
bear
question
When an apple that weighs 1 N is held at rest above your head, the net force on the apple is
answer
0 N
question
A heavy object and a light object in a vacuum are dropped at the same time from rest. The heavy object reaches the ground
answer
at the same time as the light object
question
A given net force propels an object along a straight-line path. If the net force were doubled, its acceleration would
answer
double
question
When you toss a ball upward, after the ball leaves your hand
answer
none of the above
question
A hockey puck slides across a frozen pond. If ice friction and air resistance are neglected, the force needed to keep the puck sliding at constant velocity is
answer
0 N
question
A ball is thrown vertically upward. At the top of its vertical path, its velocity is
answer
0 m/s
question
An object in motion tends to remain in motion
answer
without the need of a force.
question
If you drop an object, it will accelerate downward at a rate of 10 m/s2. If you instead throw it downward, its acceleration (in the absence of air resistance will be
answer
10 m/s^2
question
A light woman and a heavy man jump from an airplane at the same time and open their same—size parachutes at the same time. Which person reaches a state of zero acceleration first?
answer
the light woman
question
A commercial jet has a mass of 5000 kg. During takeoff the thrust of its engine is 10,000 N, producing an acceleration of
answer
2 m/s^2
question
A car traveling at 100 km/h strikes an unfortunate bug that splatters on the windshield. The force of impact is greater on the
answer
same for both
question
A 1000-kg car accelerates at 2 m/s2. What is the net force exerted on the car?
answer
2000 N
question
If you jump straight up while inside a fast-moving train that gains speed, you land
answer
slightly behind your original position
question
A car by itself is capable of a certain maximum acceleration. When it tows a car of the same mass, its maximum acceleration is
answer
half
question
When a baseball player hits a ball with a force of 1000 N, the ball exerts a force on the bat of
answer
1000 N
question
If your automobile runs out of fuel while driving, the engine stops. You don't come to an abrupt stop because of
answer
inertia
question
A stone is thrown vertically upward. At the top of its vertical path its acceleration is
answer
10 m/s^2
question
When dishes remain on a table when you yank the tablecloth beneath them, you're demonstrating
answer
inertia
question
An archer shoots an arrow. If the action force is the bowstring on the arrow, the reaction is the
answer
arrow's push on the bowstring
question
A vase sits at rest on a table. If the action force is Earth pulling downward on the vase, the reaction force is the
answer
vase pulling upward on Earth
question
A force of 1 N accelerates a 1-kg mass at 1 m/s2. The acceleration of a 2-kg mass acted upon by a force of 2 N is
answer
the same
question
If gravity between the Sun and Earth suddenly vanished, Earth would move in
answer
a straight-line path
question
A player hits a ball with a bat. If one part of the interaction is the bat against the ball, the other part is the
answer
ball against the bat
question
A Mack truck and a Mini Cooper traveling at the same speed collide head-on. The collision force is greatest on the
answer
same on both
question
If an object falls with constant acceleration, the velocity of the object must
answer
continually change by the same amount each second
question
The air resistance of falling is greatly affected by an object's frontal area and
answer
speed
question
A pair of tennis balls fall through the air from a tall building. One ball is regular and the other is filled with lead pellets. The ball to reach the ground first is the
answer
lead-filled ball
question
The force exerted on the tires of a car to directly accelerate the car along a road is exerted by the
answer
road
question
Jake pulls on a 25-kg cart with a constant force of 50 N. What is the wagon's acceleration?
answer
2.0 m/s^2
question
If a non-rotating object has no acceleration, then we can say for certain that it is
answer
in mechanical equilibrium
question
You cannot exert a force on a wall
answer
unless the wall simultaneously exerts the same amount of force on you
question
A block is dragged at constant velocity across a level surface by a force of 6 N. What is the force of friction between the block and the surface?
answer
6 N
question
If you are learning to juggle it would be good to slow the ball's acceleration. You can do this by using
answer
none of the above
question
A tow truck exerts a force of 3000 N on a car that accelerates at 2 m/s2. What is the mass of the car?
answer
1500 kg
question
Joshua is attracted toward Earth by a 500-N gravitational force. The Earth is attracted toward Joshua with a force of
answer
500 N
question
As drops fall from a leaky faucet they become
answer
farther apart as they fall.
question
A martial arts person breaks a board with a blow of 3000 N. The force that acts on the hand is
answer
3000 N
question
Inertia is defined as a
answer
property of matter
question
The emphasis of the orange-and-apple sequence in your text is
answer
to define systems.
question
When an object falls through the air, as velocity increases the net force
answer
decreases
question
When a rock thrown straight up reaches the exact top of its path, its velocity is
answer
zero and its acceleration is 10 m/s^2.
question
When you step off a bus moving at 2 m/s, your horizontal speed when you meet the ground is
answer
about 2 m/s
question
A skydiver jumps from a high-flying plane. As her velocity of fall increases, her acceleration
answer
decreases
question
A parachutist steps from a hovering helicopter and falls for 5 s before reaching terminal velocity. During this 5-s interval, her acceleration
answer
decreases
question
When you toss a coin straight up, it moves upward, turns around, and drops. During all this time the acceleration of the coin is
answer
downward and constant
question
A sack of potatoes weighing 200 N falls from an airplane. As the velocity of fall increases, air resistance also increases. When air resistance equals 200 N, the sack's acceleration is
answer
0 m/s^2
question
Nellie whirls a tether ball in a horizontal circular path over her head. If the action force is Nellie pulling on the string, the reaction force is
answer
the sting pulling on Nellie
question
Arnold Strongman wearing socks and Suzie Small in gym shoes have a tug-of-war on a polished floor. The likely winner is
answer
Suzie
question
A falling object that has reached its terminal speed continues to gain
answer
none of the above
question
A friend says that the heavyweight champion of the world cannot exert a force of 50 N on a piece of tissue paper with his best punch. The tissue paper is held in midair, no tricks. You
answer
agree that it can't be done
question
The acceleration of a rocket increases as it travels upward from the ground mainly because
answer
the mass of the rocket decreases as fuel is burned
question
When you rub your hands together, you
answer
cannot push harder on one hand than the other
question
How many forces act on an upwardly tossed coin when it gets to the top of its path?
answer
one; the force due to gravity
question
The force of a boxer's punch is greater when it hits a
answer
heavy punching bag
question
Earth exerts a force on the Moon. These two bodies make up
answer
one interaction
question
A skydiver who weighs 500 N reaches terminal velocity at 90 km/h. The air resistance on the skydiver is
answer
500 N
question
A space probe in remote outer space continues moving
answer
even though no force acts on it
question
If an object's mass is decreasing while a constant force is applied to the object, the acceleration
answer
increases
question
A pair of tennis balls fall through the air from a tall A pair of tennis balls fall through the air from a tall building. One ball is regular and the other is filled with lead pellets. Air resistance just before they hit is greater for the
answer
lead-filled ball
question
Action and reaction forces are parts of
answer
a single interaction
question
A 10-kg brick and a 1-kg book are dropped in a vacuum. The acceleration of the 10-kg brick is
answer
the same as that of the 1-kg book
question
If you jump vertically while inside a fast-moving train that is slowing down, you land
answer
a bit ahead of your original position.
question
Earth moves about 30 km/s relative to the Sun. When you jump upward in front of a wall, the wall doesn't slam into you at 30 km/s because the wall
answer
and you move at the same horizontal speed, before, during, and after your jump.
question
A math book and a science book are tied together with a length of string. With the string taut, one book is pushed off the edge of a table. As it falls, the other book is dragged horizontally across the table surface. With no friction, acceleration of the books is
answer
between zero and g.
question
A moving van with a stone lightly glued to the midpoint of its ceiling smoothly moves at constant velocity. When the glue gives way, the stone falls and hits the floor
answer
exactly below the midpoint of the ceiling
question
A heavy rock and a light rock in free fall have the same acceleration because the
answer
ratio of force to mass is the same
question
A push on a 1-kg brick accelerates the brick. Neglecting friction, to equally accelerate a 10-kg brick requires the force to be
answer
10 times as much
question
A heavy block at rest is suspended by a vertical rope. When the block is accelerated upward by the rope, the rope tension
answer
is greater than its weight.
question
A Mack truck and a Mini Cooper traveling at the same speed collide head-on. The vehicle to undergo the greatest change in velocity will be the
answer
Mini Cooper.
question
A stone is thrown vertically upward. At the top of its vertical path the force acting on it is
answer
only the force due to gravity.
question
The attraction of Earth on a skydiver pulls the diver downward. The reaction to this force is
answer
none of the above
question
If the mass of an object does not change, a constant net force on the object produces constant
answer
acceleration.
question
Newton's second law focuses on
answer
acceleration.
question
When a rocket ship gaining speed in remote, gravity-free outer space runs out of fuel, it
answer
no longer gains speed.
question
The net force on any object moving at constant velocity is
answer
zero
question
A player catches a ball. Consider the action force to be the ball against the player's glove. The reaction is the
answer
force of the glove on the ball
