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.
