Final Exam Physical Science

What is the acceleration of a car that maintains a constant velocity of 100 km/hr for 10 seconds?

0

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

10 times as much as the force on the 1kg brick

Ten seconds after starting from rest, a freely falling object (g=10m/s2) will ahve a speed of about:

100m/s

The average speed of a horse that gallops a distance of 10km in a time of 30 minutes:

20km/hr

A man weighing 800N stands at rest on two bathroom scales so that his weight is distributed evenly over both scales. The reading on each scale is:

400N

Starting from rest, the distance a freely falling object (g=1m/s2, and d=1/2gt2)will fall in 10 seconds is:

500m

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

6N

A block is dragged without acceleration in a straight-line path a cross a level surface by a force of 6N. What is the force of friction between the block and the surface?

6N

A projectile is launched at an angle of 15 degree above the horizontal and lands downrange. what other projectile angle for the same speed would produce the downrange distance?

75 degree

A projectile hits the surface of the earth at some point, if its speed is:

<8000m/s

The principle which states that an immersed body is buoyed by a force equal to the weight of the fluid it displaces is:

Archimedes' principle

A coin and a feather dropped in a vacuum will have the same momentum.

False

A machine with a power output of 500W, for every input of 1000W, is said to have an efficiency of 25%.

False

Acceleration is the rate of change of distance per unit time.

False

An object in motion comes to a stop without any external force.

False

Any completely immersed body displaces a quantity of fluid equal to its own weight.

False

Barometer is any device that measures the density of materials.

False

Escape speed from a planet decreases with increase in the mass of the planet.

False

Every 8000m, the surface of the Earth drops an approximate vertical distance of 20m.

False

Force is always expressed as a push, but not as a pull.

False

Force of interaction indicates that, when you push an object, the object will pull you.

False

Ice tends to form at the bottom of bodies of water.

False

If the same force is applied on different masses, the one with the larger mass will have a high acceleration.

False

In a freefalling object, terminal speed is attained when the force of gravity and air resistance are equal.

False

In the same locality, the ratio of force to mass results in the same gravitational acceleration.

False

Inertia is the quantity of matter in an object.

False

Kinetic energy is energy of an object because of its location.

False

Kinetic energy is the stored energy that a body possesses because of its position.

False

Mass is the resistance of an object to a change in state of motion.

False

Terminal speed is the speed at which the acceleration of a falling object terminates when air resistance balances its weight.

False

The horizontal speed of a projectile is influenced by gravity.

False

The law of inertia holds true only for objects in motion, but not for those at rest.

False

The pressure in liquid decreases with depth.

False

The resistance of most conductors to the flow of charge decreases with increase of temperature.

False

The weight of a given object is the same on Earth and on the Moon.

False

Volume indicates how much matter an object contains.

False

When a falling object attains terminal velocity, gravitational acceleration will be the highest.

False

When the mass of an object is decreased while a constant force is applied on it, the acceleration of the object decreases.

False

Work is the product of force and the distance through which the force moves.

False

Work is the product of force and time

False

The critical speed at which a projectile outruns gravity is called terminal speed.

False (Escape Speed)

Acceleration is the resistance of an object to a change in state of motion.

False (inertia)

A completely submerged object displaces its volume of fluid.

True

Action and reaction forces are equal in strength and opposite in direction.

True

An Earth satellite is simply a projectile freely falling around the Earth.

True

An astronaut in space feels weightless.

True

Every object possesses inertia

True

Friction is the resistive force that opposes motion or attempted motion of an object.

True

If you double the velocity of a moving object with constant mass, its momentum will double.

True

In circular orbit, the speed of a satellite is the same everywhere.

True

In the absence of friction, no force is required to keep a horizontally moving object moving.

True

In vacuum, the acceleration of a free falling feather and stone is equal.

True

It takes relatively short time to boil water at higher altitude than at sea level.

True

Motion under the influence of gravitational force only is called free fall.

True

Potential energy of an object is because of its location.

True

Salty water is denser than fresh water.

True

The density of fish is equal to the density of water.

True

The mass of a given object is the same on Earth and on the Moon.

True

The ratio of gravitational force (F) to mass (m) is the same for all objects in the same locality.

True

Weightlessness is the condition encountered in free fall wherein a support force is lacking.

True

A feather and a coin dropped in a vacuum fall with equal:

acceleration

The rate of change of velocity with time (in magnitude, direction or both)is called:

acceleration

When you stand at rest on a pair of bathroom scales, the readings on the scales will always:

add equal to your weight

Which one has zero acceleration? An object

all of the above

The resistive force of friction occurs for:

all of these

In the vacuum of outer space, there is no:

atmospheric pressure

Any device that measures atmospheric pressure is called:

barometer

If an object's mass is increased, while a constant force is applied to the object, its acceleration:

decreases

A freight train rolls along a track with considerable momentum. If it rolls at the same speed but has twice as much mass, its momentum is:

double

If the mass of an object were to double while its volume remains the same, its density would:

double

The critical speed at which a projectile outruns gravity is called:

escape speed

It is simply stated as a push or a pull.

force

A car that travels twice as fast as another, when breaking to a stop will skid:

four times as far

Motion under the influence of gravitational pull only is called:

free fall

A heavy truck and a small car rolling down a hill at the same speed are forced to stop in the same amount of time. Compared to the force that stops the car, the force needed to stop the truck is

greater

If the volume of an object were to double while its mass stays the same, its density would:

halve

Atmospheric pressure is:

higher at sea level than at the top of a very high mountain

Two objects move toward each other because of gravity. as the objects get closer, the force between them

increases

When the distance between two stars decreases by half, the force between them:

increases four times as much

The property of things to resist changes in state of motion is called:

inertia

Ice floating on water indicates that the the density of ice is:

less than the density of water

According to Newton, the greater the distance between masses of interacting objects, the:

less the gravitational force between them

An object that has potential energy may have this energy because of its:

location

When you are on the way of a fast moving object and can't get out of its way, you will suffer a smaller force of impact if you decrease its momentum over a:

long time

Force is a vector quantity because it has:

magnitude and direction

Force per unit area is called:

pressure

Any object that moves through the air or through space under the influence of gravity is called:

projectile

As a ball falls, the action force is the pull of the Earth's mass on the ball. The reaction force is the:

pull of the ball's mass on the Earth

A measure of how fast something is moving is called:

speed

The force that an object exerts on a supporting surface is called:

support force

The speed at which the acceleration of a falling object terminates when air resistance balances its weight is called:

terminal velocity

Compared with the same mass of a certain object on Earth, the mass of the same object on the Moon is:

the same

Neglecting friction, a large block of ice and a small block of ice start sliding down an incline together. The heavier block will get to the bottom:

the same time as the light block

If you push an object just as far while applying twice the force, you do:

twice as much work

If you do work on an object in half the time, your power output is:

twice the usual power

When a chocolate bar is cut in half, its density is:

unchanged

Space occupied by a given mass is called:

volume

A feeling encountered in free fall wherein a support force is lacking is called:

weightlessness

The force required to maintain an object at constant velocity in free space is equal to

zero

When a falling object has reached its terminal velocity, its acceleration is:

zero