Physics 10

Two billiard balls having the same mass roll toward each other, each moving at the same speed. What is the combined momentum of the two balls?

0 kg m/s

A 1-kg chunk of putty moving at 1 m/ s collides and sticks to a 5-kg bowling ball initially at rest. The bowling ball and putty then move with a momentum of

1 kg·m/s

A rifle of mass 2 kg is suspended by strings. The rifle fires a bullet of mass 0.01 kg at a speed of 200 m/s. The recoil velocity of the rifle is about

1 m/s

A 1-kg glider and a 2-kg glider both slide toward each other at 1 m/s on an air track. They collide and stick. The combined mass moves at

1/3 m/s

On a balanced see saw, a boy three times as heavy as his partner sits

1/3 the distance from the fulcrum

A 1-kg chunk of putty moving at 1 m/s collides with and sticks to a 5-kg bowling ball that is initially at rest on a frictionless surface. The speed of the putty thereafter is

1/6 m/s

An apple falls from a tree and hits the ground 5 meters bellow. It hits the ground with a speed of about

10 m/s

Disregarding air drag, how fast must you toss a ball straight up in order for it to take 2 seconds to return to the level from which you tossed it?

10 m/s

If a freely falling object were somehow equipped with a speedometer, its speed reading would increase each second by about

10 m/s

What is the buoyant force acting on a 10-ton ship floating in the ocean?

10 tons

a metal block has a density of 5000 kg per cubic meter and a volume of 2 cubic meters. What is the blocks mass..?

10,000 kg

The mass of a cubic meter of water is

1000 kg

A car accelerates at 2 m/s/s/ Assuming the car starts from rest, how far will it travel in

100m

A car accelerates at 2 m/s/s. Assuming the car starts from rest, how much time does it need to accelerate to a speed of 30 m/s?

15 seconds

A ball moving 3 m/s has the momentum of 48 kg m/s. What is the balls mass

16 kg

A rock suspended by a string weighs 5 N out of water and 3 N when submerged. What is the buoyant force on the rock?

2 N

Suppose the circumference of a bicycle wheel is 2 meters. If it rotates at 1 revolution per second when you are riding the bicycle, then your speed will be

2 m/s

A 1000-kg car moving at 10 m/s brakes to a stop in 5 s. The average braking force is

2000 N

An object at rest near the surface of a distant planet starts to fall freely. If the acceleration there is twice that of the Earth, its speed one second later would be

20m/s

An object falls freely from rest on a planet where the acceleration due to gravity is twice as much as it is on Earth. In the first 5 seconds it falls a distance of

250 m

A 4kg ball has a momentum of 12kg m/s. What is the balls speed?

3 m/s

A 300-kg bear grasping a vertical tree slides down at constant velocity. The friction force between the tree and the bear is

300 N

At one instant a heavy object in air is moving upward at 50 m/s. One second later its speed is approximately

40 m/s

A 5-kg fish swimming at a speed of 1 m/s swallows an absent-minded 1-kg fish at rest. The speed of the larger fish after this lunch is

5/6 m/s

a wooden block has a mass of 1000kg and a volume of 2 cubic centimeters. What is the blocks density...?

500 kg per cubic meter D=M/V

If a car increases its velocity from zero to 60 km/hr in 10 seconds, its acceleration is

6 km/h/s

A 5000-kg freight car runs into a 10,000-kg freight car at rest. They couple upon collision and move with a speed of 2 m/s. What was the initial speed of the 5000-kg car?

6 m/s

If a car accelerates from rest at 2 meters per second per second, its peed 3 seconds later will be about

6 m/s

At one instant an object in free fall is moving downward at 50 m/s. One second later its speed should be about

60 m/s

If you drop an object, it will accelerate downward at a rate of 9.8 meters per second. If you instead throw it downwards, its acceleration (in the absence of air resistance) will be

9.8 m/s/s

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

About 1/10 as great

Science is a body of knowledge that

Describes order in nature, is an ongoing activity of humans, condenses knowledge into testable laws.

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

Doubled

The scientist to first introduce the concept of inertia was

Galileo

Padded dashboards are safer in cars than no padding because the occupation hitting the dash has

Increased time of impact

Which of the following is a scientific statement?

The moon is made of green cheese.

A ball is thrown 125 meters upward and then falls the same distance back to Earth. Neglecting air resistance, its total time in the air is

about 10 seconds

It takes 6 seconds for a stone to fall to the bottom of a mine shaft. How deep is the shaft?

about 180 m

A package falls off a truck that is moving at 30 m/s. Neglecting air resistance, the horizontal speed of the package just before it hits the ground is

about 30 m/s

Disregarding air resistance, objects fall with constant

acceleration

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

add up to equal your weight.

According to Newton's Law of inertia, a railroad train in motion should continue going forever even if its engine is turned off. We never observe this because railroad trains

always have forces that oppose their motion.

Which of the following involves passion, talent, and intelligence?

art, literature, music, science

Which has zero acceleration? An object

at rest, moving at constant velocity, mechanical equilibrium

An object in mechanical equilibrium is an object

at rest, moving with constant velocity, having no acceleration.

In drinking soda or water through a straw, we make use of

atmospheric pressure.

A bubble of air released from the bottom of a lake

becomes larger as it rises

Water pressure is greatest against the

bottom of a submerged object

In a vacuum on earth, an object has no

buoyant force

If an object moves with constant acceleration, its velocity must

change by the same amount each second

If no external forces are acting on a moving object, it will

continue moving at the same speed.

The pressure in a liquid depends on liquid

density and depth

A ball tossed vertically upward rises, reaches its highest point, and then falls back to its starting point. During this time the acceleration of the ball is always

directed downward

The two measurements necessary for calculating average speed are

distance and time.

if the mass of an object were to double while its volume remains the same, its density would...?

double

When gas in a container is squeezed to half its volume and the temperature remains the same, the gas pressure

doubles

According to the impulse-momentum equation Ft = change in (mv), a person will suffer less injury falling on a wooden floor which "gives" than on a more rigid cement floor. The "F" in the above equation stands for the force exerted on the

either the force on the person or the force on the floor

A truck is moving at constant velocity. Inside the storage compartment, a rock is dropped from the midpoint of the ceiling and strikes the floor below. The rock hits the floor

exactly below the midpoint of the ceiling.

The scientific method is most effective in

gaining, organizing, and applying new knowledge.

Momentum is transferred to the ground when an apple falls on it. The momentum absorbed by the ground is

greater than that of the apple only if the apple bounces.

In science, an educated guess is a

hypothesis.

A karate expert executes a swift blow and severs a cement block with her bare hand. The magnitude is the same for the

identical to the force applied to the block

If the Earth rotated more slowly about its axis, your apparent weight would

increase

If your automobile runs out of fuel while you are driving, the engine stops you do to come to an abrupt stop. The concept that most explains why is

inertia

Compared to a 1-kg block of solid iron, a 2-kg block of solid iron has twice as much

inertia mass volume

Ice cubes submerged at the bottom of a liquid indicate that the liquid

is less dense than ice.

A force is a vector quantity because it has both

magnitude and direction

Two objects have the same size and shape, but one is much heavier than the other. When they are dropped simultaneously from a tower, they reach the ground at the same time, but the heavier one has a greater

momentum

Compared to the density of a kilogram of feathers, the density of a kilogram of lead is

more

A block of wood half as dense as water floats with half its volume above water. A piece of iron is then tied on top so the wood floats with only 1/4 its volume above the surface. If the wood and iron are turned over so that the iron is submerged beneath the wood, then the volume of wood above the water surface will be

more than 1/4

Twelve seconds after starting from rest, an object falling freely will have a speed of

more than 100 m/s

When a rocket ship accelerating in outer space runs out of fuel, it

no longer accelerates

Starting from rest, the distance a freely falling object will fall in .5 second is about

none of the above.

A 1-N apple falls to the ground. The apple hits the ground with an impact force of about

not enough information given to say

A large heavy truck and a small baby carriage roll down a hill. Neglecting friction, at the bottom of the hill, the baby carriage will have a greater

nothing

Which moves faster in m/s on a merry-go-round: a horse on the inside or a horse on the outside near the outer rail?

outside horse

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

physics.

When water is turned on in a shower, the shower curtain moves towards the water. This has to do with

pressure of a moving fluid

A suction cup sticks to a wall. It is

pushed to the wall by the atmosphere

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

right.

Two people are balanced on a seesaw. If one person leans inward toward the center of the seesaw, that person's end of the seesaw tends to

rise

The statement, "There are regions beneath the Earth's crust that will always be beyond the reach of scientific investigation," is a

speculation

A ring, a disk, and a solid sphere begin rolling down a hill together. The one to reach the bottom first

sphere

Your weight is

the gravitational attraction force between you and the Earth

A rock weighs 30 N on Earth. A second rock weighs 30 N on the moon. Which of the two rocks has the greater mass?

the one on the moon

The flight of a blimp best illustrates

the principle of Archimedes

For a system in mechanical equilibrium

the resultant forces and torques must both be zero

A ball is thrown upwards and returns to the same position. Compared with its original speed after release , its speed when it returns is about

the same

Compared to the mass of a certain object on Earth, the mass of the same object on the moon is

the same

Drop a rock from a 5-m height and it accelerates at 10 m/s^2 and strikes the ground 1 s later. Drop the same rock from a height of 2.5 m and its acceleration of fall is about

the same amount

You know that you can safely stand on the overhanging end of a heavy plank that rests on a table. How far out depends on your mass and the mass of the plank. Suppose you can stand on the end of a plank that overhangs the edge of the supporting table 1 4 its total length. Then how massive is the plank compared to your mass?

the same as your mass

The synthesis of a large collection of information that contains well-tested and verified hypotheses about certain aspect of the world is known as a scientific

theory

A flywheel's mass is twice that of another of the same size and shape. The more massive flywheel's rotational inertia is

two times the other's.

The reason that buoyant force acts upward on a submerged object is that

upward pressure against the bottom is greater than downward pressure against the top of the submerged object.

While an object near the Earth's surface is in free fall, its

velocity increases

A completely submerged object always displaces its own

volume of fluid

A balloon is buoyed up with a force equal to the

weight of air it displaces

Atmospheric pressure is caused by the

weight of the atmosphere

A car maintains a constant velocity of 100 km/hr for 10 seconds. During this interval its acc. is

zero