Physics 3

A ball is thrown upward and caught when it comes back down. In the presence of air resistance, the speed with which it is caught is

less than the speed it had when thrown upward

Most Natural phenomena we wonder about

involve several scientific disciplines

A force is a vector quantity because it has been

magnitude and direction

Density is the ratio of

mass to volume

In Science, Facts

may change

A baseball player bats a ball with a force of 1000N. The ball exerts is a reaction force against the bat of

1000N

What is the net force on a box that is being pushed to the left with a force of 40N while its also being pushed to the right with a force of 50N

10N to the right

Wind is blowing at 15m/h into rows of wind-powered generators(windmills). What might the wind speed be after it goes through the wind powered generator.

10m/h

A 4Kg ball has a momentum of 12Kg*m/s what is the ball's speed

12/4= v=3 M=V/M= 12/M

A karate chop delivers a force of 3000N to a board that breaks. The force that the board exerts on the hand is

3000N

A girl pulls on a 10Kg wagon with a constant force of 30N. Neglecting friction, what is the wagon's acceleration in m/s2

30n/ 10kg 3m/s2

Which requires more work: Lifting a 50Kg sack vertically 2m or Lifting a 25Kg sack vertically 4m

50*10=f m=25*10=f d=2 d=4 500*2 250*4 1000 1000 Both require the same amount of work

What is the force of gravity on a 500N women standing on Earth's surface

500N

A projectile is launched vertically at 50m/s. If air resistance is negligible, its speed upon returning to its starting point is

50m/s

an object is pulled northward with a force of 10N and Southward with a force of 15N. the magnitude of the net force of the object is

5N

Whereas Aristotle relied on logic in explaining nature. Galileo relied on

experiment

Weight is

the gravitational attraction between you and the earth

If the sun were twice as massive

the pull on the Earth on the sun would double and the pull on the earth would double

In order to catch, a ball a baseball player extends the hand forward before impact with the ball and lets it ride backward in the direction of the balls motion upon impact. doing this reduces the force of impact on the player's hand by

the time of impact is increased

As an object freely falls its

velocity increases

A man weighing 800N stands at a rest on two bathroom scales so that his weight is distributed evenly on both scales, resting on each scales is

400N

What is the force of gravity on a 600N man standing on Earth's Surface

600N

A car accelerates from rest at 2m/s2. What is its speed 3s after the car starts moving?

6m/s

How much force, or thrust must a 20,000kg jet plane develop to achieve an acceleration of 2m/s2

F=MA =20,000kg(2) F= 40,000N

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

F=MA F=1000kg*2m/s2 F=2000N

The scientist to first introduce the concept of inertia was

Galileo

A kilogram is a measure of an objects?

Mass

Two objects, A and B have the same size and shape, but A is twice as heavy as B, when they are dropped simultaneously from a tower, they reach the ground at the same time, but A has greater

Momentum

Compared with a 1.0kg block of solid iron, a 2.0kg block of solid iron has the same

it doesnt have the same anything, volume, weight and mass.

An object that has kinetic energy must be

moving

The force of gravity acts on all apples on an apple tree. Some apples are twice as far as the other. These twice as far as high apples, for the same mass have

practically the same weight

Science and Technology are

related to one another but not the same thing

A truly educated person is knowledgable about

science, religion, and the arts

It is correct to say that impulses is equal to

the change in momentum

The force that allow you to walk is

the friction of the floor on your foot and the reaction force of your foot against the floor

According to Newton, the greater the masses of interacting object is

the greater the gravitational force between them

Technology

the means of solving a problem by applying the findings of science

The reason that the mood does not crash into the Earth is that

the moon has a sufficient tangential speed.

An example of scientific hypothesis

the moon is made of green cheese

An object is raised above the ground gaining a certain amount of potential energy, if the same object is raised twice as high it gains

twice as much potential energy

An object is raised above the ground gaining a certain amount of potential energy. If the same object is raised twice as high it gains

twice as much potential energy

A 1000kg car and a 2000kg car are hoisted the same distance in a gas station. Raising the more massive car requires

twice as much work

A scientific hypothesis may turn out to be right or it may turn out to be wrong, If its a valid hypothesis there must be a test for proving it

wrong

An educated guess is a

Hypothesis

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

be constant also

An airplanes flies at 40m/s at an altitude of 50m. The pilot drops a heavy package, which falls and strikes the ground. Where approx does the package land

beneath the plane

Your driving down the highway and a bug splatters on your windshield, which undergoes the greater change in momentum?

both have the same momentum

When a rifle is fired, it recoils so both the bullet and rifle are set in motion, the rifle and bullet ideally acquire equal

but opposite amounts of momentum

In 2.0 seconds, a car increases its speed from 30 Km/h to 35km/h while a bicycle goes from rest to 4 Kim/h. Which has the greatest acceleration?

car v1=30 vf=35 5, 5/2=2.5 bike Vi=0 Vf=4 change 4 4/2=2 the car

A rock is thrown upward at 50 degree with respect to the horizontal. As it rises, its vertical components of velocity

decreases

when a loaf of bed rises, its density

decreases

Mass(quantity of matter) and Weight (force due to gravity) are

directly related to each other

If experimental findings are not reproducible

the results are not considered valid

A ball is thrown upward and caught when it comes back down. Neglecting air resistance, how does the speed, just before it is caught compares to the original speed?

the same as

Railroad Car A rolls at a certain speed and collides elastically with railroad car B of the same mass. After the collision, Car A is at rest. How does the speed of Car B after the collision compare with the initial speed of Car A

the same speed

In Science, A theory is

a synthesis of a large body of well-tested knowledge

The property of a system that enables it to do work

Energy

A moving object has

Energy, speed, momentum and Velocity

When you whirl an object at the end of a string in a circular path what is the direction of centripetal force that acts on the object?

Toward the center

A person weighs 150lbs, the Earth is pulling down on that person with a force of 150 pounds. The person is pulling up on the Earth with a force of 150 pound. True or False

True

In the absence of external work input or output, the energy of a system remains unchanged. Normally energy cannot be created nor destroyed

True

A TV set is pushed a distance of 2m with a force of 20N that is in the same direction as the set moves. How much work is done on the set.

20N*2M=40NM

Which has a greater mass? An automobile battery or a king-sized pillow

an automobile battery

Thinking of the inverse-square relationship, how does the thickness of paint sprayed on a surface change when the sprayer is held twice as far away and the sprayed for the same length of time

1/4 as thick

A hockey puck is set in motion across a frozen pond. If ice friction and air resistance are neglected, the force required to keep the puck sliding at constant velocity is

0.0N

An apple weights 1.0N when held at rest above your head, the net force on the apple is

0.0N

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

10 N

Earth's Satellites are typically more than 100km high so as above Earths..... Man made satellites such as the space shuttle orbit at altitudes that are above Earth's

Atmosphere

of the sciences known as physics, chemistry and biology, the most basic is

Physics

The statement "There are regions beneath Earth's Crust that will always beyond reach of scientific investigation is an example of

Speculation

Science

The collective findings of humans, about nature, and a process of gathering and organizing knowledge about nature

When you jump from an elevated position, you usually bend your knees upon reaching the ground. By doing this, the time of impact is about 10 times more for a stiff-legged landing. In this way the average force your body is experiences is reduced by

about 10 times

Hang from a pair of gym rings and the upward support forces of the rings will always

add up equal to your weight

Science, Art and religion do not contradict one another because

all three have different domains

The graph at the right is a graph of \

an indirect proportion

Inside a freely falling runaway elevator, your

apparent weight is zero

What involves passion, talent and intelligence

art, music, science, and literature

A heavy object and a light object are dropped at the same time from rest in a vacuum. The heavier object reaches the ground

at the same time as the lighter object

The two measurements necessary for calculating average speed are

distance and time

Whereas impulse involves the time that a force acts, work involves the

distance that a force acts

According to Newton's law of inertia, the result of walking around much of the day is similar to tightening the head of the hammer when its handle hits a solid surface so that we are actually a little bit but shorter in the

evening

Whirl a rock at the end of a string and it follows a circular path. If the String breaks, the tendency of the rock is to

follow a straight line path

An object is propelled along a straight-line path in space by a force. If the mass of the object somehow becomes twice as much its acceleration

halves