Physics Exam-1

An apple weighs 1N, when held on head the net force on apple is

0N

A sack of potatoes weighing 200N falls from an airplane. As the velocity of fall increases air resistance also increases when air resistance equal to 200N what is the sack's acceleration?

0m/s²

A bullet is dropped from a tall skyscraper while another bullet is forced downwards from the same place. Neglecting air resistance, acceleration is greater for.

10 m/s² for each.

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

10 times as much as the force on 1kg book

An apple weight 1N, the net force on apple in free fall is

1N

What is required to keep asteroid moving for billion of years out in deep space?

Nothing and this property is called as Inertia

When a very massive object with small a small mass collides

On impact the forces on each mass are the same but the more massive object experiences a smaller acceleration

In which case would the bottom of a paper bag carrying groceries be most likely to be ripped open?

The bag of groceries is accelerated upwards.

A object weigh 30N on earth. second object weight 30N on moon. which one has greater mass?

The one on moon,

As a ball fall the action force is the pull of the earth's mass on the ball. What us the reaction to this force?

The pull of the ball's mass on earth.

A feather and a coin will have equal acceleration when falling in a vacuum( no air resistance) because

The ration of the objects weight to its mass is the same.

A horse exerts 500N of force on a heavy wagon. The wagon pulls back on the horse with equal force. The wagon is still accelerating because

There is still net force acting on the wagon.

When a rock thrown straight upwards gets to the exact top of its path its

Velocity is zero and its acceleration is about 10 m/s²

A mack truck and volkswagen traveling at the same speed have a head on collision. The vehicle to undergo the greatest change is velocity will be

Volkswagen

A object is projected straight up and eventually falls back, if you include air resistance, then the time it took to travel upwards compared to its time to make the same distance travel downwards is

a longer time on the way down and shorter time on the way up.

A moving object on which no force is acting will continue to move

at a constant velocity

A heavy object and a light object are dropped at the same time from rest in a vacuum, The heavier object will reach the ground

at the same time as the light object

If an object falls with constant acceleration the velocity of the object

continually change by the same amount each second

Suppose a particle is accelerated through a space(no gravity) with a 10N force suddenly the particle encounters a second charge opposite direction while the first force is still present. The particle

continued at the speed it had when it encountered the second force.

When an object falls through the air, its velocity increases and its acceleration

decreases

A truck is moving with a constant velocity. Inside the storage compartment a rock dropped from the mid point of the ceiling and strickes the floor below. The rock hits the floor

exactly at the midpoint of the ceiling.

Among other things NTL says that

force is an interaction between 2 bodies.

Weight

gravitational attraction to the earth

A object falling a straight line path at constant speed

has zero acceleration

When you start to walk altering standing from rest, the force of friction of the ground on you is

in the same direction as you are walking

As an object freely falls its

velocity changes.

If a freely falling object were some how equipped with speedometer its speed reading would be increasing each second by about

10m/s

If you drop an object it will accelerate downwards at a rate of 10m/s². If you instead throw it downwards its acceleration (absence of air resistance) will be

10m/s²

A car is accelerates at 3m/s². What is the speed 4 sec after the car started moving from rest?

12 m/s

The mass of the dog that weights 300N is about

30 kg

A man weighs 800N stands on 2 bathroom scales; one foot on each side. The reading on scale is 400N so what will be the reading on other scale

400N

Two people pull on a rope with a tug of war. Each pull with 400N of force. What is a tension in a rope?

400N

A package falls off a truck that is moving at 40m/s horizontally. Neglecting air resistance, the horizontal speed of the package just before it grounds is

40m/s

An object is in a free fall moving in the vertical direction only. At one instant its traveling at a speed of 55m/s. Exactly after one second later its speed is about

45m/s

Skydiver mass 100kg experiences 500N air resistance. What is his or her acceleration? g=10m/s²

500/100=5a 5a=.5g Ans=.5g

A person is attracted towards the center of earth by 500N. Gravitational force the force that the earth is attached towards the person is

500N

A man falling through the air weighs 500N , air resistance 800↑, what is magitude of the force acting on the person and what direction?

500N↓-800N↑=300N↑

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

6N

Disregards air resistance object fall at constant

Acceleration

A 100N bag of groceries is at rest on the ground. How much force is necessary to make the groceries accelerate upwards

Anything greater than 100N

If a body is speeding up, then you know that

Body's velocity is parallel to its acceleration.

Mass is a measure of an objects

Inertia

Object has twice mass as another object. The first object has twice as much as

Inertia

An object maintains its state of motion because it has

Mass

Compared to the weight on earth a 10kg object at moon will weight

less

If the velocity of an object and its acceleration are oppositely directed

means body is slowing down.

NTL says that

only an even number of total forces can be exerted on a body.

Compared to the mass on earth mass on the moon will be

same

Newtons second law says that if the acceleration of body is zero then

the sum of all forces acting on the body must be zero.

As far as comparing gravitational mass and inertial mass

they have same numbers but different concepts.