B) an automobile battery
Which has the greater mass?
A) a king-size pillow
B) an automobile battery
A kilogram is a measure of an object’s
D) all of these
Compared to a 1-kg block of solid iron, a 2-kg block of solid iron has twice as much
E) none of these
Compared to a 1-kg block of solid iron, a 2-kg block of solid iron has the same
E) none of these.
An object maintains its state of motion because it has
the gravitational attraction between you and the Earth.
Your weight is
One object has twice as much mass as another object. The first object also has twice as much
Compared to the mass of a certain object on Earth, the mass of the same object on the moon is
the mass of the car is independent of gravity.
Strange as it may seem, it is just as hard to accelerate a car on the moon as it is to accelerate the same car on Earth. This is because
An empty roller-coaster car at an amusement park takes 3 minutes to make its ride from start to finish.
Neglecting friction, a fully loaded car would take
The newton is a unit of
In which case would you have the largest mass of gold? If your chunk of gold weighed 1 N on the
the one on the moon
An object weighs 30 N on Earth. A second object weighs 30 N on the moon. Which has the greater mass?
An object’s weight may properly be expressed in
magnitude and direction.
A force is a vector quantity because it has both
10 times as much as the force on the 1-kg book
A 10-kg brick and a 1-kg book are dropped in a vacuum. The force of gravity on the 10-kg brick is
An object is propelled along a straight-line path by a force.
If the net force were doubled, the object’s acceleration would
If an object’s mass is decreasing while a constant force is applied to the object, the acceleration
An object is propelled along a straight-line path in space by a force.
If the mass of the object somehow becomes twice as much, its acceleration
An object is pulled northward with a force of 10 N and southward with a force of 15 N.
The magnitude of the net force on the object is
The force of friction on a sliding object is 10 newtons.
The applied force needed to maintain a constant velocity is
A 10-N falling object encounters 4 N of air resistance. The net force on the object is
A 10-N falling object encounters 10 N of air resistance. The net force on the object is
An apple weighs 1 N. When held at rest above your head, the net force on the apple is
An apple weighs 1 N. The net force on the apple when it is in free fall is
D) all of these.
Which has zero acceleration? An object
A) at rest.
B) moving at constant velocity.
C) in mechanical equilibrium.
Whenever the net force on an object is zero, its acceleration
The maximum acceleration of a car while towing a second car twice its mass, compared to no towing, is
continue moving at 40 km/h in the absence of forces
Suppose you’re coasting on level ground in a car at 60 km/h and apply the brakes until you
slow to 40 km/h. When you suddenly release the brake, the car tends to
A heavy block at rest is suspended by a vertical rope.
When the block is accelerated upward by the rope, the rope tension
A 1-kg mass at the earth’s surface weighs
in mechanical equilibrium
If a non-rotating object has no acceleration, then we can say for certain that it is
add to equal your weight
When you stand at rest on a pair of bathroom scales, the readings on the scales will always
add up to equal your weight.
Hang from a pair of gym rings and the upward support forces of the rings will always
A car has a mass of 1000 kg and accelerates at 2 meters per second per second.
What is the magnitude of the net force exerted on the car?
A tow truck exerts a force of 3000 N on a car, accelerating it at 2 meters per second per second.
What is the mass of the car?
A girl pulls on a 10-kg wagon with a constant horizontal force of 30 N.
If there are no other horizontal forces, what is the wagon’s acceleration in meters per second per second?
If the mass of an object does not change, a constant net force on the object produces constant
A force of 1 N accelerates a mass of 1 kg at the rate of 1 m/s2.
The acceleration of a mass of 2 kg acted upon by a net force of 2 N is
A bag of groceries has a mass of 10 kilograms and a weight of about
The mass of a pet turtle that weighs 10 N is about
The force required to maintain an object at a constant velocity in free space is equal to
has zero acceleration
An object following a straight-line path at constant speed
A man weighing 800 N stands at rest on two bathroom scales so that his weight is distributed
evenly over both scales. The reading on each scale is
at the same time as the light block
Neglecting friction, a large block of ice and a small block of ice start sliding down an incline together.
The heavier block will get to the bottom
When a woman stands at rest with two feet on a scale, the scale reads 500 N. When she gently lifts one foot,
the scale reads
10 times as much force
A push on a 1-kg brick accelerates the brick. Neglecting friction, to equally accelerate a 10-kg brick,
one would have to push with
10 times as much force on the heavier block
A 10-N block and a 1-N block lie on a horizontal frictionless table. To push them with equal acceleration,
we would have to push with
the mass of the rocket decreases as fuel is burned
A rocket becomes progressively easier to accelerate as it travels upward from the ground mainly because
A rock is thrown vertically into the air. At the very top of its trajectory the net force on it is
A rock is thrown vertically into the air. At the top of its path, its acceleration in meters per second per second is
A block is dragged without acceleration in a straight-line path across a level surface by a force of 6 N.
What is the force of friction between the block and the surface?
continues at the speed it had when it encountered the second force
Suppose 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 from the first force.
The particle with both forces acting on it
A jumbo jet has a mass of 100,000 kg. The thrust for each of its four engines is 50,000 N.
What is the jet’s acceleration in meters per second per second when taking off?
A 1-kg rock that weighs 9.8 N is thrown straight upward at 20 m/s. Neglecting air resistance,
the net force that acts on it when it is half way to the top of its path is
A 1-kg ball is thrown at 10 m/s straight upward. Neglecting air resistance, the net force that acts
on the stone when it is halfway to the top of its path is about
The brakes of a speeding truck are slammed on and it skids to a stop.
If the truck were heavily loaded so that it had twice the total mass, the skidding distance would be
A skydiver of mass 100 kg experiences air resistance of 500 N, and an acceleration of about
An object released from rest on another planet requires one second to fall a distance of 6 meters.
What is the acceleration in meters per second per second due to gravity on this planet?
A car traveling at 22 m/s comes to an abrupt halt in 0.1 second when it hits a tree.
What is the deceleration in meters per second per second of the car?
A 10-kilogram block with an initial velocity of 10 m/s slides 10 meters across a horizontal surface
and comes to rest. It takes the block 2 seconds to stop. The stopping force acting on the block is about
A 10-kilogram block is pushed across a horizontal surface with a horizontal force of 20 N against
a friction force of 10 N. The acceleration of the block in meters per second per second is
If you are driving at 20 m/s and slam on your brakes and skid at 0.5 g to a full stop,
the skidding time in seconds is about
A 1000-kg automobile enters a freeway on-ramp at 20 m/s and accelerates uniformly up to 40 m/s in a time of 10 seconds. How far does the automobile travel during that time?
A 2000-kg car experiences a braking force of 10,000 N and skids to a stop in 6 seconds.
The speed of the car just before the brakes were applied was
An astronaut on another planet drops a 1-kg rock from rest and finds that it falls a vertical
distance of 2.5 meters in one second. On this planet, the rock has a weight of
What horizontally-applied force will accelerate a 400-kg crate at 1 m/s2 across a factory floor
against a friction force half its weight?
About 5000 N
The human body can, under certain conditions, withstand an acceleration of 10 g. What net
force would produce this acceleration of a 50-kg person?
If an object of constant mass experiences a constant net force, it will have a constant
the object accelerates in the direction of the applied force.
If more horizontal force is applied to a sliding object than is needed to maintain a constant velocity,
the object eventually slides to a stop
If less horizontal force is applied to a sliding object than is needed to maintain a constant velocity,
size and speed of the object
Two factors that greatly affect air resistance on falling objects are the
When a falling object has reached its terminal velocity, its acceleration is
Two objects of the same size, but unequal weights are dropped from a tall tower.
Taking air resistance into consideration, the object to hit the ground first will be the
the light woman
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 will get to a state of zero acceleration first?
get a larger parachute.
A large and a small person wish to parachute at equal terminal velocities.
A skydiver, who weighs 500 N, reaches terminal velocity of 90 km/h.
The air resistance on the diver is then
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 in meters per second per second is
An elephant and a feather fall from a tree through the air to the ground below.
The amount of air-resistance force is greater on the
When an object falls through the air, its velocity increases and its acceleration
A skydiver jumps from a high-flying plane. As her velocity of fall increases, her acceleration
A skydiver steps from a helicopter and falls for 5 seconds before reaching her terminal velocity.
300 N upward
A 500-N parachutist opens his chute and experiences an air resistance force of 800 N.
The net force on the parachutist is
A ball is thrown vertically into the air. Because of air resistance, its speed when it returns to its starting level compared to its initial speed is
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
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 actually greater for the
A ball is thrown vertically into the air. Because of air resistance, its time coming down compared to its time going up is
less than 5 s.
88) A ball thrown straight upward takes 10 seconds to go up and return to the ground. Because of air resistance, the time taken for the ball just to go up is
A falling skydiver of mass 100 kg experiences 500 N air resistance. The acceleration of the skydiver is
An astronaut on another planet drops a 1-kg rock from rest. The astronaut notices that the rock falls 2 meters straight down in one second. On this planet, how much does the rock weigh?
the ratio of each object’s weight to its mass is the same
A feather and a coin will have equal accelerations when falling in a vacuum because
A skydiver’s terminal velocity will be greatest if she falls