Chapter 4 Cuellar

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

1 kg

A 1kg mass at the Earths surface weighs

10 N

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

10 N

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

10 times as much force

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

10 times as much force

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

100 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

10N

The mass of a lamb that weighs 110 N is about

11 kg

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

1500 kg

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?

2 m/s^2

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

2000 N

A car traveling at 22 m/s comes to an abrupt halt in 0.1 seconds when it hits a tree. what is the deceleration of the car?

220 m/s^2

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

30 m/s

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

300 N upward

If you are driving at 20 m/s and slam on your brakes and skid at 0.5g to a full stop, the skidding time is about

4 s

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 force on the phone is

5 N

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 becomes

0 m/s^2

Skydiver of a mass of 100 kg experiences air resistance of 500N, and an acceleration of about

0.5 kg

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

500 N

Calculate the weight in newtons of a person having a mass of 56 kg

560 N

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

6 N

If a motorcycle moves with a constant acceleration, can you conclude that there is no net force acting on it?

No

since an object weighs less on the surface of the moon than on the Earth;s surface does it have less inertia on the Moon's surface

No

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

greater on the coconut

if the mass of the cart is quickly loaded to have twice the mass while propelling force remains constant, the carts acceleration

halves

A skydivers terminal velocity will be greatest if she falls

head first

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

heavier object

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

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

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

increases

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

is greater than its weight

If the net force on a cart is tripled, the carts acceleration

is three times as much

The mass of a rocket decreases as it burns through its fuel. If the rocket engine produces constant force (thrust), how does the acceleration of the rocket change over time?

it increases

A kilogram is a measure of an objects

mass

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

mg

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

one half

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

speed

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

the same

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

the same

What happens to the weight reading on a scale you stand on when you toss a heavy object upward

the scale reading will increase during the throw

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

top string

When a parachutist opens her parachute after reaching terminal speed, in what direction does she accelerate?

up

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

zero

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

zero

A boulder following a straight line path at a constant velocity

zero acceleration

If more 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

Recall Galileos leaning tower experment. With neglible air resistance,a heavy and a light object fall

all of the above

Which has zero acceleration? An object

all of the above

Which has the greater mass>

an automobile battery

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

an upward support force

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

at the same time as the small block

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

0 N

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

0 N

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?

The heavy man

Newton's second law relates an object's acceleration to its mass and the net force acting on it. Does Newton's second law apply to a situation in which there is no net force? Select the best explanation.

Yes the law applies and it tells us that the object has a constant velocity

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

bottom string

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

continue moving at 40 km/h

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

eventually slides to a stop

The newton is a unit of

force