physics ch 4

10 N

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

10 N

A 1-kg mass at the Earth's surface weighs

10 N

A 1-kg rock that weighs 10 N is thrown straight upward at 20 m/s. Neglecting air resistance, the net force that acts on it when it is halfway to the top of its path is

10 times more than the force on the apple

A 10 kg brick and a 1 kg apple are dropped in a vacuum. The force of gravity on the brick is

10 times as much force

A 10-N block and a 1-N block lie on a horizontal frictionless table. To impart equal horizontal accelerations, we would have to push the heavier block with

0 N

A 10-N falling object encounters 10 N of air resistance. The net force on the object is

6 N

A 10-N falling object encounters 4 N of air resistance. The net force on the object is

1 m/s2

A 10-kg 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 is

300 m

A 100-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?

30 m/s

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

3000 N

A 300-kg bear grasping a vertical tree slides down at constant velocity. The friction force between the tree and the bear is

300 N upward

A 500-N parachutist opens his chute and exoerience an air resistance force of 800 N. The net force on the parachutist is then

zero acceleration

A boulder following a straight-line path at constant velocity has

one half.

A car by itself is capable of a certain maximum acceleration. When it tows a car of the same mass, its maximum acceleration is

2000 N

A car has a mass of 1000 kg and accelerates at 2 m/s2. What net force is exerted on the car?

220 m/s2

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 of the car

top string

A heavy ball hangs by a string, with a second string attached to its bottom. A slow pull on the bottom string breaks the

is greater than its weight

A heavy block at rest is suspended by a vertical rope. When the block accelerates upward by the rope, the rope tension

heavy rock

A heavy rock and a light rock of the same size are falling through the air from a tall building. The one that encounters the greatest air resistance is the

2 m/s2

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 when taking off

get a larger parachute

A large and a small person wish to parachute at equal terminal velocities. The larger person will have to

the heavy man

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 the ground first?

10 times as much force

A push on a 1-kg brick accelerates it. Neglecting friction, equally accelerating a 10 -kg brick requires

mg

A rock is thrown vertically into the air. At the top of its path the net force on it is

the one on the Moon

A rock weighs 30 N on Earth and another rock weighs 30 N on the moon. Which rock has the greater mass?

0 m/s2

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

its ratio of force to mass is the same

A single brick falls with acceleration g. The reason a double brick falls with the same acceleration is

is zero

A skydiver steps from a helicopter and falls for a few seconds until terminal velocity is reached. Thereafter, until he opens his parachute, his acceleration

head first

A skydiver's terminal velocity will be greatest if she falls

1500 kg

A tow truck exerts a force of 3000 N on a car, which then accelerates at 2 m/s2. What is the mass of the car?

1 N

An apple at rest weighs 1 N. The net force on the apple when it is in free fall is

4 N

An astronaut on another planet drops 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 weight?

5 N

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

12 m/s2

An object released from rest on another planet requires one second to fall a distance of 6 meters. What is the acceleration due to gravity on this planet.

newtons.

An object's weight is properly expressed in units of

an upward support force

At equilibrium on a bathroom weighing scale, the downward pull of gravity on you is balanced by

Greater on the coconut

Coconut and a birds feather fall from a tree through the air to the ground below. The force of air resistance is

mechanical equilibrium

If a non-rotating object has no acceleration, then we can say for certain that it is

increases

If an object's mass is decreasing while a constant force is applied to the object, the acceleration

eventually slides to a stop

If less horizontal force is applied to a sliding object than is needed to maintain a constant velocity, 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

halves

If the mass of a cart is quickly loaded to have twice the mass while a propelling force remains constant, the cart's acceleration

is three times as much

If the net force on a cart is tripled, the cart's acceleration

at the same time as the small block

Neglecting friction, a small and a large block of ice begin sliding down an incline together. The larger block reaches the bottom

3.0 m/s2

Nelli epulls 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

500 N

Phil stands at rest with both feet on a scale that reads 500 N. When he gently lifts one foot, the scale reads

all of the above

Recall Galileo's Leaning Tower experiment. With negligible air resistance, a heavy and a light object fall

0.5 g

Scotty Skydriver of mass 100 kg experiences air resistance of 500 N, and an acceleration of about

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. The particle with both forces acting

decreases

Suzie Skydiver jumps from a high-flying plane. As her velocity of fall increases, her acceleration

500 N

Suzie Skydiver, who weighs 500 N, reaches terminal velocity of 90 km/h. The air resistance on Suzie is then

the same

The breaks of a speeding truck are slammed on and it skids to a stop. If the truck were heavily loaded so that it has twice the total mass, the skidding distance would be

10 N

The force of friction on a sliding object is 10 N. The applied force needed to maintain a constant velocity is

5000 N

The human body can withstand an acceleration of 10 g under certain conditions. What net force would produce this acceleration for 50-kg person?

heavier object

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

lead-filled ball

Two tennis balls fall through the air from a tall building. One of them is filled with lead pellets. The ball to reach the ground first is the

2400 N

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?

zero.

When a falling object has reached its terminal velocity, its acceleration is

in the top string is due to your pull plus the weight of the ball

When the bottom string is pulled slowly in the heavy-ball-and-strings demonstration (Figure 4.8 in your book), tension

is zero

Whenever the net force on an object is zero, its acceleration

an automobile battery

Which has the greater mass?

continue moving at 40 km/h

You drive your car at a constant 60 km/h along the highway. You apply the brakes until the car slows to 40 km/h. If at that moment you suddenly release the brakes, the car tends to

the force due to gravity on you

Your weight as measured on your bathroom scale is

100 N

a bag of groceries that has a mass of 10 kilograms weighs about

less

a ball is thrown upwards and caught when it returns. Compared with its initial speed and in the presence of air resistance, the speed with which it is caught is always

more

a ball is thrown vertically into the air. because of air resistance, it's time coming down compared to its time going up is

less than 5 s

a ball thrown straight upward takes 10 seconds for its up-and-down round trip. Because of air resistance, the time taken for the ball just to go up is

less

a ball thrown vertically into the air. Because of air resistance, its speed when it returns to its starting level compared with its initial speed is

6 N

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?

the ratio of their weights to mass is the same

a bowling ball and a baseball accelerate equally when falling in a vacuum because

one third

a car by itself is capable of a certain maximum acceleration. When it tows a twice-as-massive car, its maximum acceleration is

Acceleration

a constant net force on a rail-road car produces constant

the same

a force of 1 N accelerates 1-kg box at the rate of 1 m/s2. The acceleration of 2-kg box by a net force of 2 N is

bottom string

a heavy ball hangs by a string, with a second string attached to its bottoms. A quick pull on the bottom string breaks the

Mass

a kilogram is a measure of an object's

the light women

a light women 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

5 N

a mobile phone is pulled northward by a force of 10 N and at the same time pulled southward by another force of 15 N. The resultant on the phone is

10 m/s2

a rock is thrown vertically into the air. At the top of its path the acceleration is

0 N

an apple weights 1 N. When the apple is held at rest above your head, the net force on the apple is

Inertia

an object with twice as much mass as another object has twice as much

None of the above

compared to a 1-kg block of solid iron, a 2-kg block of solid iron has the same

all of the above

compared to a 1-kg block of solid iron, a 2-kg block of solid ironhas twice as much

the same

compared to the mass of an apple on Earth, the mass of the apple on the moon is

Acceleration

if an apple experiences a constant net force, it will have a constant

Speed

if you double the net force on an object, you'll double its

moon

in which case would you have the largest mass of gold? If your chunk of gold weighted 1 N on the

the mass of the car is independent of gravity

strange as it may seem, it is just as difficult to accelerate a car on a level surface on the Moon as it is here on Earth because

zero

the force required to maintain a constant velocity from an astronaut in free space is equal to

11 kg.

the mass of a lamb that weighs 110 N is about

1 kg

the mass of a pet turtle that weighs 10 N is about

Force

the newton is a unit of

Speed

to factors that greatly affect air resistance on falling objects are frontal area and

the mass of a rocket decreases as fuel is burned

when a constant and sustained upward force acts on a rocket, its acceleration increases mainly because

show readings that when added equal your weights

when you stand at rest with your left foot on one bathroom scale and your right foot on a similar scale, each of the scales will

all the above

which has a zero acceleration? an object