Abeka Matter and Energy Test 2 OG

Momentum

What quantity of motion is defined as the product of an object's mass and velocity ?

Aristotle

Whose teachings dominated scientific thought for almost two thousand years ?

Isaac Newton

Who discovered the laws of motion and gravitation , laying the foundation for much of modern physical science ?

9.5 m / s

What is the velocity of an object that traveled 19 m in 2.0 s ?

joule

What is the SI unit of work ?

pulley

What is a simple machine consisting of a wheel over which a rope or cable passes ?

2

What is the ideal mechanical advantage of an inclined plane with a length of 3.0 m and a height of 1.5 m ?

terminal velocity

What is the velocity at which air resistance stops a falling object from accelerating?

vector

What is any mathematical quantity that has both magnitude and direction ?

9N to the left

A crate was being pushed by one person with a force of 35N to the left, and by another person with a force of 26N to the right. What is the net force acting on the crate?

35 kg - m / s forward

What is the momentum of a 5 kg bowling ball rolling forward at 7 m / s ?

frame of reference

What is the space relative to which motion is measured ?

classical physics

Together , the branches of physics discovered before 1900 are called ?

resultant

The sum of two or more vectors is the ? .

pendulum

An object that hangs from a fixed point and swings back and forth because of gravity is a ?

speed

The distance an object travels per unit of time is ___ ?

efficiency

The measure of how well a machine converts input work to output work is ?

centripetal force

The center - seeking force that causes an object to travel in a curved path is called ?

wedge

The simple machine which is like an inclined plane that modifies the applied force and directs it to the side is the ?

F = ma

Newton's second law of motion .

d = 1/2 gt²

the relationship between free - fall distance and the acceleration of gravity

Fw = mg

the weight of an object found using Newton's second law and gravity

V=d/t

the measure of how quickly an object moves

p = mv

the momentum of an object

W = Fd

W = Fd calculating energy transferred from one object to another by force

Work is the transfer of energy from one object to another by a force .

Which of the following statements correctly describes work and energy ?

Newton's third law of motion

What principle states that for every action there is an equal and opposite reaction?

Newton's first law of motion

What principle states that the velocity of an object does not change unless the object is acted upon by an external force ?

power

What is the rate of doing work ?

mechanical advantage

What is the term for a measure of how much help a machine provides?

inclined plane

What simple machine is a sloping surface that allows an object to be raised without being lifted straight up ?

distance between two adjacent threads ( pitch )

What is the output distance of a screw ?

displacement

Which of the following quantities represents any change in an object's position ?

wheel and axle

Which device is considered a circular lever and can be used to multiply distance , speed , or force ?

gravitational force

Which of the following forces is the attractive force that exists between any two bodies and is caused by their mass ?

d. All of the above are forms of assistance that a simple machine can provide .

Which of the following is a form of assistance that a simple machine can provide ?

a . A simple machine can multiply an applied force .

b . A simple machine can multiply the distance a force moves something .

c . A simple machine can change the direction of a force .

d. All of the above are forms of assistance that a simple machine can provide .

d . arrangement of the input arm , output arm , and fulcrum

How are levers classified ?

a . whether they multiply force or speed

b. relative length of the input and output arms

c. size of the fulcrum

d. arrangement of the input arm , output arm , and fulcrum

static friction

What type of friction affects stationary objects , preventing them from moving

mechanics

What branch of physics addresses the effects of forces on matter ?

scalar

What type of quantity consists of only a magnitude , with no direction ?

watt

What Sl unit is used to measure power ?

block and tackle

What is a combination of one or more fixed pulleys and one or more movable pulleys called ?

acceleration

What term do physicists use to refer to any change in velocity ?

kinetic ( friction )

What type of friction affects a sliding object already in motion ?

machines

What is the term for devices used to multiply force for the purpose of doing work ?

dynamics

What is the study of motion and forces ?

IMA=2nr/P

the ideal mechanical advantage of a screw

Fkf= ukFw

the magnitude of kinetic friction force

P=W/t

the rate of doing work

N=Wo/Wi

the measure of how well a machine converts input into output work

IMA=di/do

the general formula for mechanical advantage under ideal conditions

d . vector , because the ordered pair includes the direction

a . scalar , because the ordered pair has only magnitudes

b . scalar , because the ordered pair includes the direction

c . vector , because the ordered pair has only magnitudes

d . vector , because the ordered pair includes the direction

a. fulcrum between input and output with long input arm ; multiplies force and changes direction

A man needs to move a large rock . He has supplies with which he can make a simple lever . Which of the following lever designs should he choose ? Why ?

a. fulcrum between input and output with long input arm ; multiplies force and changes direction

b. fulcrum between input and output with long input arm ; multiplies force but does not change direction

c. fulcrum at one end with output near it ; multiplies force and changes direction .

d. fulcrum at one end with output near it ; multiplies force but does not change direction

c . reduce the friction of the machine machine's force

What would be a good way to increase the efficiency of a machine ?

a . increase work input

b . speed up the machine

c . reduce the friction of the machine

d . change the direction of the machine's force

b . No , he should have subtracted the forces .

A student calculated that the net force acting on the car below is 49,000 N to the right . Is his answer correct ? If not , what should he have done ?

a . Yes , his answer is correct .

b . No , he should have subtracted the forces .

c . No , the net force should be to the left .

d . No he should have divided the forces .

98 m north

(Show work: 137 m north + ( -39 m south ) -98 m north)

What is the total displacement of a person who walked 137 m north and then 39 m south ?

44 m d = g² = ( 9.81 m / s² ) ( 3.0 s ) ² = 44 m

How far will an object fall if it is affected by only gravity and falls for 3.0s ?

27 N

Work: F = F = ( 0.30 ) ( 90 . N ) = 27 N

A cardboard box weighing 90. N is pushed across a hardwood floor . The coefficient of kinetic friction for cardboard on wood is 0.30 . What is the minimum force that must be applied to keep the box moving ?

360,000 N

Work: ( 180,000 . kg ) ( 2.0 m / s² ) = 360,000

What force is required to accelerate a 180,000 . kg train engine at a rate of 2.0 m / s² ?

1,770,000 N

Work: F = mg = ( 180,000 . kg ) ( 9.81 m / s2 ) 1,770,000 N

Calculate the weight of a 180,000 . kg train engine .

560 J

W=Fd=(700. N)(.80m)= 560J

Calculate the work performed by a moving crew who lifted a couch 0.80 m off the ground with a force of 700. N.

92.8 %

N=(Wo/Wi) = (50.1J/54.0J)≈92.8%

Using a simple machine , a person put in 54.0 J of work ; the work output was 50.1 J. Calculate the efficiency of the simple machine .

565

Calculate the ideal mechanical advantage of a jackscrew with a handle of 45.0 cm and a pitch of 0.500 cm . Use pi=3.14