# Concept review for final

## Presentation on theme: "Concept review for final"— Presentation transcript:

Concept review for final

An object following a straight-line path at constant speed...
Has net force in direction of motion Must be in a vacuum Has no forces on it Has zero acceleration None of the above

How does acceleration of an object change in relation to its mass?
Does not depend on mass Inversely proportional Directly proportional

The acceleration produced by the net force on an object is...
In direction of net force Inversely proportional to mass Proportional to magnitude of net force All above None of above

Heavy and light person parachute together…identical ‘chutes, open ‘chute at same time. Which one hits ground first? Heavy guy Light guy Same time

A 10kg brick and a 1kg book are dropped in a vacuum
A 10kg brick and a 1kg book are dropped in a vacuum. The force of gravity on the 10kg brick is ________ . Same as force of gravity on 1kg book Zero Ten times the force of gravity on the 1kg book

Suppose the force of friction on a sliding object is 10N
Suppose the force of friction on a sliding object is 10N. Force needed to maintain constant velocity is _____ Less than 10 N More than 10 N 10N

An object has a constant mass
An object has a constant mass. A constant force on an object produces constant Acceleration Velocity Both 1 and 2 None of the above

If @ 20mph it takes 30 feet to stop, @ 40mph it takes _______ feet, given the same braking force.
300 60 90 120 40

As a ball falls, the action force is the pull of the earth on the ball
As a ball falls, the action force is the pull of the earth on the ball. The reaction force is _______________. Ball’s acceleration Pull of ball on the earth Zero Air resistance None of the above

If a horse pulls on a wagon at rest, the wagon pulls back equally on the horse. Will the wagon move?
No, as forces cancel Yes, as a net F is on wagon Yes, as horse pull on wagon is greater than wagon pull on horse Yes because of time delay between action/reaction

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A block of iron is heated and expands. Its density became________ .
Lower Higher Same as it was.

Water pressure against a submerged object is greater against the _______ .
Top Same on all surfaces Sides Bottom None of the above

When first placed in the water, a boat will sink until _______.
It displaces a W of water equal to its W It displaces a volume of water equal to its volume Buoyant F equals boat volume Water density equals boat density

A block of balsa wood floats on water, same size block of lead lies at the bottom. Buoyant force is ________. Greater on wood Greater on lead Same on both

If a weighted, air-filled balloon sinks in a lake it will _______.
Be buoyed up with constant F while sinking Sink until it reaches equilibrium, then stay there Sink then rise later Always sink None of above

In a vacuum on earth, an object has no _____________.
Heat Temperature Mass Weight Buoyant force

Which has larger buoyant force, a balloon filled with He or the same size balloon filled with air?... Helium balloon Air balloon Neither – same.

Bernoulli’s principle states that as____________.
Volume of gas increases, pressure decreases Fluid pressure increases, fluid speed increase Fluid pressure increases, fluid speed decreases Volume increases, pressure increases

Umbrellas tend to move up on a windy day as__________________.
Air trapped under umbrella pushes it up. Low pressure is created above the umbrella Buoyancy increases with increasing wind speed None of the above

When representing velocity as a vector _______________.
Direction of arrow shows direction of motion Length of arrow represents speed Length of arrow is drawn to scale All of above

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Which of the following is NOT a projectile?
Cannonball fired at a target Cannonball fired straight up Cannonball rolling down a ramp Cannonball rolling off cliff All the above

A ball is thrown into the air at some angle
A ball is thrown into the air at some angle. At the very top of its trajectory, its velocity is _______________. Vertical and horizontal Not enough info. To determine it Entirely Vertical Entirely Horizontal

A ball is thrown into the air at some angle
A ball is thrown into the air at some angle. At the very top of its trajectory, its acceleration is _______________. Vertical and horizontal Entirely Vertical Entirely Horizontal -10m/s2 Both 2 and 4

A ball launched horizontally hits the ground in 0. 5s
A ball launched horizontally hits the ground in 0.5s. If launched at a much higher speed in the same direction it .. Would take longer than 0.5s to land Would Take 0.5s to land Would Take less than 0.5s to land

A dropped ball has an acceleration of g
A dropped ball has an acceleration of g. If it had been thrown at an angle, its acceleration would be _________. G downward Less than g 1g upward None of the above

After a ball is thrown up and reaches the top, what is its acceleration as it falls back down?.
Same as it was when at the top Greater than it was at the top Less than it was at the top

A rock is thrown at 42. 5° above the ground
A rock is thrown at 42.5° above the ground. If it moves 8m horizontally in the first second, how far does it move horizontally in the next second More than 8m Less than 8m 8m Not enough information

The resultant of a 4m vector and a 3m vector perpendicular to each other is_______.
None of the above

The resultant of a 4m vector and a 3m vector perpendicular to each other is_______.
None of the above

The resultant of a 4m vector and a 3m vector in same direction is_______.
None of the above

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Satellites like the international space station orbiting the earth have __________________________.
No gravity force on them Almost no gravity force Almost the same gravity force as we experience on earth Path of horizontal projectile 3 and 4 above

The reason satellites orbit at least 100mi above the earth is _______.
No gravity up there No air up there To keep out of the way of planes and birds To avoid mountains All of the above

Heat is _____________. How hot an object is
Energy transferred from hot objects to cold objects Measured in degrees Average amount of kinetic energy of particles

Heat is measured in ______ .
Joules Calories Kilocalories All the above

The largest extremes of temperature are usually experienced _____...
Near oceans On islands In the middle of continents In Japan In Ireland In Florida

Mix some 10°C water and some 20°C water and the final temperature is _°C
15 Depends on masses of each used

Convection is __________.
EM waves travelling from hot to cold Large numbers of atoms moving from place to place Energy from one atom transferring to other atom Atoms giving off IR

Conduction is __________.
EM waves travelling from hot to cold Large numbers of atoms moving from place to place Energy from one atom transferring to other atom Atoms giving off IR

Which of the above expands most when temperature is lowered?.
Water Wood Iron None of the above

When water @ 4°C is heated it expands, when water at 4°C is cooled it _________.
Neither expands nor contracts Contracts Expands

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Convection is restricted to _____.
Solids Liquids Gases Fluids None of the above

Wearing silver clothing reduces energy loss from the body by ______
Conduction Convection Radiation Friction None of the above

If a poor emitter of radiation were a good absorber of radiation, then the temperature of this object would be ____ Same as surroundings Warmer than surroundings Cooler than surroundings None of the above

Global warming is because the atmosphere with excess CO2 is less transparent to _____ .

A piece of metal will generally feel colder than a piece of wood at the same temperature. Why?
Metals have higher specific heat Metal is colder Metals conduct heat better Wood is a bad insulator Metal atoms move slowly

Two identical size and shape cups are filled with boiling water
Two identical size and shape cups are filled with boiling water. One is white, the other black. Which cools fastest? Black White Same Not enough information

When snow forms in clouds due to liquid water freezing, the surrounding air gets ________
Warmer Colder Stays same

When can you expect the length of night and day worldwide to be equal
When can you expect the length of night and day worldwide to be equal? Date(s) in _____ March June September December September and June September and March

Potential energy is energy an object has due to its ___________.
Position Temperature Size Density speed

The amount of potential energy possessed by an elevated object is __ .
Distance lifted Work done in lifting G Power used to lift it

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A job is done slowly, an identical job is done quickly, both jobs require different amounts of ________. Work Energy Power None of the above

When a ball thrown up with KE = 100J encounters air resistance, the kinetic energy when it reaches the ground Is 100J Less than 100J More than 100J Not enough information

An object that has KE must have___.
Acceleration A force on it Momentum None of above

Which has greater KE, a ball travelling at 20mph or a ball half the mass travelling at 40mph? .
Heavy ball Light ball Same

A heavy object and a light object are released at same time in a vacuum. As they fall they have equal _____ Force of gravity on them Momenta Energy All of above None of above

If the velocity of a moving object doubles, what else doubles?
Kinetic energy Acceleration Momentum All above None of the above

A small car and a heavy car are pushed with equal forces an equal distance, which receives more KE?.
Large car Small car Both same

How much work is done by carrying a 50N rock horizontally across a 10m room?
50J 5J 10J 500J 0J

If a car has 2000J of KE, and it doubles its speed, how much KE will it have?

A 10N object moves at 1m/s. Its KE is _______ .
More than 10J 10J 1J 0.5J

In order to increase the final momentum of a golf-ball we could __.
Increase force on it Increase time of contact between club and ball Both 1 and 2

The reason dashboards in cars are padded is _______.
They feel nice Decrease momentum of collision Increase force of a collision Increase time of a collision

If you are standing on a wet, frozen pond where there is NO friction, you can get off the ice by ____. Crawl off ice Walk very slowly Bend over and bring feet to hands, repeat Throw something in direction opposite to where you want to go

Suppose a gun were made of a very light material such that it was similar mass to the projectile. Then…... It would have less recoil Conservation of energy would be violated The target would be a safer place to be than where operator is. Force on projectile is greater than force on gun

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