Physics Final
How much does it cost to burn a 6W (.0006KW) light bulb for 24 hours if energy costs $0.07/KWhr?
$0.01
Two automobiles, each of mass 1300kg, are moving at the same speed, 34 m/s, when they collide and stick together. At what speed does the wreckage move if one car was driving north and one east?
24 m/s
What is the torque exerted on a bolt by a 20N force exerted perpendicular to a 0.1m wrench?
2Nm
A 5kg block is pushed across a horizontal surface with a horizontal force of 35N against a friction force of 20N. The magnitude of the acceleration of the block is...
3 m/s
An 600N man stands at rest on two bathroom scales so that his weight is distributed evenly over both scales. The reading on each scale is...
300N
An un-stretched hanging spring is 25cm long. Suspending a 10N block from it increases its length to 28cm. Adding another 10N block makes the spring's length...
31cm
A ball rolls off a tall horizontal table at a speed of 3 m/s. It takes one second for it to reach the floor. How far from the base of the table did the ball hit?
3m
A 2kg rifle that is suspended by strings fires a 0.02kg bullet at 300m/s. The recoil velocity of the rifle is about...
3m/s
Neglecting air resistance, if a projectile is fired straight up at a speed of 20 m/s, the total time to return to its starting position is about...
4 seconds
A projectile is fired horizontally from the top of a tall cliff with a horizontal speed of 20 m/s. After 3 seconds, how far has the projectile fallen below the top of the cliff?
45m
The power required to exert 8N force over 2 meters in 4 seconds is...
4W
A 2000kg freight car moving at 6m/s collides with a 1000kg freight car at rest. They couple upon collisions and move away at...
4m/s
An apple released from rest on another planet requires 4 seconds to fall a distance of 40 meters downward. What is the acceleration due to gravity on this planet?
5 m/s downward
A 5kg fish moving at 1m/s swallows an absent minded 1kg fish at rest. The speed of the larger fish after lunch is...
5/6 m/s
An atom has an atomic number 39 and atomic mass 89. How many neutrons does this atom have?
50
A solid block of aluminum has an upward buoyant force of 5N when submerged so that the top of the block is a depth of 1m. What is the buoyant force if this same block is now submerged at a depth of 10M?
5N
How does the greenhouse effect work?
Earth's surface is warmed by the sun causing the surface to emit infrared radiation. The radiation is strongly absorbed by CO2 gas in the atmosphere which warms the atmosphere.
To a fair approximation, Eratostheses, Aristarchus, and other early Greeks were able to determine by making measurements the...
Earth-Moon distance, size of the Moon, and size of the Earth
If you do not use a seat belt and are in collision in a car, you may be thrown through the windshield. The Physics involved is best summed up by...
Newtons's First Law
A bird sitting on the limb of a tree is moving about 30 km/s with respect to the Sun. If the bird takes 1 second to drop down to a worm below, the worm would be 30km downrange from the bird when it reached the ground. This faulty reasoning is best concerned with...
Newtons's First Law, the law of inertia
Which of the following is NOT true in regard to Physics?
Once something is accepted as fact in Physics it is a fact for all time and will never change
If you double your speed in a car, how does it change your stopping distance (assuming the force of friction does not change)?
Quadruples it
Which of the following is NOT a characteristic of the scientific attitude?
Scientist do not accept experimental finds when they are not what they hoped for or expected
A beach ball can be suspended in a moving column of air from a fan and be quite stable there. What confines the ball in the moving column of air?
The Bernoulli principle as the moving column of air exerts a low pressure on the ball and is surrounded by higher pressure air
A hollow ring and a solid disk roll down a hill together. Which will reach the bottom first?
The Disk
A feather and a bowling ball are in a closed room. When air in the room is evacuated, they are simultaneously dropped from the ceiling. Which of the following is NOT true?
The force of gravity on the ball is the same as the force of gravity on the feather
What does it mean for a gas to be a greenhouse gas?
The gas is in the atmosphere and the molecules of the gas strongly absorb infrared radiation from the ground
Consider a heavy and light person jumping together with the identical, same size parachutes from the same altitude. Which of the following is NOT true?
The light person reaches the ground first
Particles of dust suspended in liquid water are observed to jiggle about. What is this phenomena called and how is it interpreted?
This is Brownian motion and the jiggling is interpreted as being caused by collisions between the dust and unseens atoms
Which of the following is a vector quantity?
Velocity
Which will remain the same for two identical books, one lying flat and the other standing on an end?
Weight
If a sodium atom gives up its outermost electron to a chlorine atom to form salt, the sodium atom is now considered...
an ion
Most of the nuclei of the atoms that make up your body are...
billions of years old
In the US, our chief source of energy is...
burning fossil fuels like petroleum, natural gas, and coal
When an object is wholly immersed in a liquid, it is buoyed up...
by a force equal to the weight of liquid displaced
A cannonball recoils while firing a cannonball. The speed of the cannon's recoil is relatively small because the...
cannon has much more mass than the cannonball
When the curve of arch matches the inverted image of a drooping chain held at both ends, the curve is called a...
catenary
The discovery of the Higgs boson will likely...
change our idea of what it means for matter to have mass
Two identical golf carts move at different speeds. The faster cart has twice the speed and therefore has...
four times the kinetic energy
A cannonball following a parabolic path explodes into fragments. The net momentum of all the fragments...
give a resultant that continues along the path as if the explosion didn't occur
An educated scientific guess is a...
hypothesis
In absence of external forces, momentum is conserved in...
in both elastic and inelastic collisions
If you stand on a weighing scale and suddenly the atmosphere vanishes, taking buoyancy into account, the scale reading...
increases
When a twirling ice skater brings her arms inward, her rotational speed...
increases
Air bags in cars are safer in accident than hard dashboards because passengers hitting the air bags encounter...
lengthened time of contact
When an object weighing 30N is falling on Earth and encounters 12N of air resistance, the magnitude of its acceleration at that point in the fall is...
less than g
An object has gravitational potential energy due to its...
location
A kilogram is a measure of an object's...
mass
When a cannon is fired, the acceleration of the cannon and the cannonball are different because the...
masses of each are different
A same size iron ball and wooden ball are dropped simultaneously from a tower and reach the ground at the same time. Neglect air resistance. The iron ball has greater...
momentum
If a monkey floating in outer space throws his hat away, the hat and the monkey will both...
move away from each other, but at different speeds
The primary cause of tides on Earth is...
the gravitational field of the moon is stronger on the side near the moon and weaker on the side farther away
A revolutionary idea set forth by Galileo was..
the idea of inertia which implies a moving object needs no force to keep it moving if no net force is actin ton it
Tidal friction on Earth is causing...
the rotation rate of the Earth to slow down very gradually and the moon to very gradually move farther away
Compared to the MASS of an apple on Earth, the mass of the apple on the Moon is...
the same
The maximum height to which water can be drunk through a straw is...
10.3 meters
A 3N falling object encounters 3N of air resistance. The net force on the object is...
0N
On a balanced seesaw, a boy three times as heavy as his partner sits...
1/3 the distance from the fulcrum
Nellie pulls on a 5kg wagon with a constant horizontal force of 60N to the right. If there are no other horizontal forces, what is the wagon's acceleration?
12m/s to the right
A 15kg mass at the Earth's surface weighs...
150N
The force of a friction on a sliding box is 150N. The applied force needed to maintain a constant velocity is...
150N
Tripling the linear size of an object multiplies its cross sectional area by...
9 and its volume by 27
Bert weighs 600N and Ernie weighs 800N. They are on a scaffold that weighs 500N. The tension in one rope supporting the scaffold is 1000N. What is the tension in the other rope on the other side?
900N
I am an extremely charismatic person, and i believe light things rise, heavy things fall, the heavier the thing the faster it falls, Earth is heavy so it cannot move. Who am I?
Aristotle
Astronauts in the International Space station appear to float or weightless in space. Which of the following best describes why this is so?
Astronauts have no weight in orbit because they are actually in free fall. Freely falling makes them appear weightless but they still have mass
Why can we not use powerful optical microscopes using visible wavelengths to see individual atoms?
Atoms are much smaller than the wavelengths of visible light
Two billiard balls having the same mass and speed roll directly toward each other. What is their combined momentum after they collide and bounce off each other?
Zero
Protons and neutrons are made up of...
a combonation of three small particles that have fractional electrical charge called quarks
A machine the promises more energy output than input is...
a fantasy
A theory in the field of science is...
a synthesis of a large body of well tested knowledge
It takes 5 seconds for a stone to fall to the bottom of a mine shaft. Neglect air resistance. How deep is the shaft?
about 125m
The famous Leaning Tower of Pisa doesn't topple over because its center of gravity is...
above a place of support
If an apple experiences a constant net force, it will have a constant...
acceleration
If you double the net force on an object, you will double its...
acceleration
A ball tossed vertically upward rises, reaches its highest point, and then falls back to its starting point. Neglect air resistance and only consider the ball after it leaves your hand and before its caught. During this time of flight the acceleration of the ball is best described as...
constant and directed downward
A vehicle undergoes acceleration when it...
decreases in speed, changes its direction, and gains speed
A ball tossed vertically upward rises, reaches its highest point, and then falls back to its starting point. Neglect air resistance and only consider the ball after it leaves your hand and before its caught. During the time of flight the absolute magnitude of the velocity of the ball...
decreases to zero at the highest point of the ball's trajectory and then increases again
If a loaf of bread is compressed its...
density increases
When a gas in a container is squeezed to half its volume with no change in temperature, the gas pressure...
doubles
Your pet hamster sits on a record player that has a constant angular speed. If the hamster moves to a point twice as far from the center, then its linear speed...
doubles
The volume of an atom is due mostly to its...
electrons
A moving object has...
energy, speed, velocity, and momentum
The force that accelerates a rocket in outer space is exerted on the rocket by the...
exhaust gases
Although solid matter is mostly empty space, we don't fall through the floor because...
of electrical forces
According to Newton, when the distance between two interacting objects doubles, the gravitational force is...
one-quarter
The number of protons in a NEUTRAL atom is balanced by an equal number of...
orbital electrons
Two protons removed from an neon nucleus results in...
oxygen
Inertia is defined as...
property of matter described as mass
A support force is an example of...
static equilibrium
If no external torque acts on a system...
the angular momentum of the system will remain constant
A ball rolling down an incline has its maximum kinetic energy at...
the bottom
The reason a life jacket helps keep you afloat is..
the density of both you and the jacket together is less than your density alone
A block of wood that weighs 25N is floating in a pond. Knowing this we also know that...
the weight of the water displaced by the floating block of wood is also 25N
If a net force on a cart is tripled and its mass stays the same, the cart's acceleration will bee...
three times as much
A 1000kg car and 2000kg car are hoisted to the same height. Raising the more massive car requires...
twice as much work
A consequence of tidal friction on the Moon due to the Earth's gravitational field is...
we only see one side of the Moon from the Earth
The buoyant force of the atmosphere on a body is equal to the...
weight of air displaced
A creature that is scaled up in size, keeping its proportions,...
will be weaker relative to its greater weight
The amount of force needed to sustain motion of a rock in outer space where there is no net force acting on it is...
zero
A asteroid in deep space following a straight-line path at constant velocity has...
zero acceleration