PHSC 235 FINAL REVIEW
A bullet is dropped into a river from a very high bridge. At the same time, another bullet is fired from a gun, straight down towards the water. Neglecting air resistance, the acceleration just before striking the water
-is the same for each bullet
Whenever the net force on an object is zero, its acceleration
-is zero
A ball is thrown vertically into the air. Because of air resistance, its speed when it returns to its starting level compared to its initial speed is
-less
A force is a vector quantity because it has both
-magnitude and direction
A kilogram is a measure of an object's
-mass
A heavy rock and a light rock in free fall have the same acceleration. The reason the heavy rock doesn't have a greater acceleration is that the
-ratio of force to mass is the same
A pair of tennis balls fall through the air from a tall building. One ball is regular and the other is filled with lead pellets. The ball to reach the ground first is the
-same for both
The resistive force of friction occurs for
-solids -liquids -gases -ALL OF THESE
Your weight is
-the gravitation attraction between you and the Earth
A sheet of paper can be withdrawn from under a container of mil without toppling it if the paper is jerked quickly, This best demonstrates that
-the milk carton has inertia
An object weighs 30N on Earth. A second object weighs 30N on the Moon. Which has a greater mass?
-the one on the Moon
compared with the mass of a certain object on Earth, the mass of the same object on the Moon is
-the same
If you push a crate across a level floor at constant speed, the friction between the crate and the floor is
-the same amount as your pushing force
Two objects of the same size, but unequal weights are dropped from a tall tower. taking air resistance into consideration, the object to hit the ground first will be the
-they both hit at the same time
As an object freely falls, its
-velocity increases
A skydiver falls toward Earth. The attraction of Earth on the diver pulls the diver down. What is the reaction to this force?
-water resistance that will soon act upward on the diver -air resistance the diver encounters while falling -the attraction to the planets, stars, and every particle in the universe -all of these -NONE OF THESE
When a falling object has reached its terminal velocity, its acceleration is
-zero
When a rock thrown straight upwards gets to the exact top of its path, velocity is
-zero and its acceleration is about 10m/s/s
An object is pulled northward with a force of 10 N and southward with a force of 15N. Magnitude of the net force on the object is
-5N
One-half second after starting from rest a freely falling object will have a speed of about
-5m/s
If a care increases its velocity from zero to 60km/h in 10s, its acceleration is
-6km/h/s
Which has the greater mass?
-AUTOMOBILE BATTERY -king-size pillow -both about the same
the scientist to first introduce the concept of inertia was
-Galileo
Arnold Strongman and Suzie Small each pull very hard on opposite ends of a rope in a tug-of-war. The greatest force on the rope is exerted by
-Suzie, surprisingly -Arnold of course -BOTH THE SAME, INTERESTINGLY ENOUGH
A Mack truck and a Volkswagon traveling at the same speed have a head on collision. The vehicle to undergo the greatest change in velocity will be the
-Volkswagon
A package falls off a truck that is moving at 30m/s. Neglecting air resistance, the horizontal speed of the package just before it hits the ground is
-about 30m/s
When you stand at rest on a pair of bathroom scales, the readings on the scales will always
-add equal to your body weight
Hang from a pair of gym rings and the upward support forces of the rings will always
-add up to equal your weight
Your friend says that the heavyweight champion of the world cannot exert a force of 50-N on a piece of tissue paper with his best punch. The tissue paper is held in midair, no wall, no tricks. You...
-agree that it can't be done
An object in mechanical equilibrium is an object
-all of the above
An archer shoots an arrow. Consider the action force to be the bowstring against the arrow. The reaction to this force is the
-arrow's push against the bowstring
which has zero acceleration? An object
-at rest -in mechanical equilibrium -moving at constant velocity -ALL OF THE ABOVE
A heavy object and a light object are dropped at the same time from rest in the vacuum. the heavier object reaches the ground
-at the same time as the lighter object
suppose you're coasting in a car at 60km/h and apply the brakes until you slow to 40km/h. When you suddenly release the brake, the care tends to
-continue moving at 40km/h in the absence of forces
Suppose a particle is being accelerated through space by a 10-N force. Suddenly the particle encounters a second force of 10 N in the opposite direction of the first force. The particle with both forces acting on it
-continues at the speed it had when it encountered the second force
The two measurements necessary for calculating average speed are
-distance and time
An object is propelled along a straight-line path by a force. If the net force were doubled, its acceleration would
-double
an object is propelled along a straight-line path by a force. if the net force were doubled, its acceleration would
-double
An elephant and a feather fall from a tree through the air to the ground below. The amount of air-resistance force is greater on the
-elephant
According to Newton's law of inertia, the result of walking much of the day is similar to tightening the head of a hammer when its handle hits a solid surface so that we are actually a little bit shorter in the
-evening
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
Whereas Aristotle relied on logic in explaining nature, Galileo relied on
-experiment
A player hits a ball with a bat. The action force is the impact of the bat against the ball. The reaction to this force is the
-force of the ball against the ball
A player catches a ball. Consider the action force to be the impact of the ball against the player's glove. The reaction to this force is the
-force the glove exerts on the ball
if a freely falling object were somehow equipped with an odometer to measure the distance it travels, then the amount of distance it travels each succeeding second would be
-greater than the second before
an object is propelled along a straight-line path in space by force. If the mass of the object somehow becomes twice as much, its acceleration
-halves
The amount of friction that occurs when two material surfaces slide against each other depends on
-how much they are pressed together -the stickiness of atoms on their surfaces -BOTH OF THESE
If a nonrotationg object has no acceleration, then we can say for certain that it is
-in mechanical equilibrium
If an object's mass is decreasing while a constant force is applied to the object, the acceleration
-increases
If you are carrying a heavy bag of groceries and bang your hand against the wall, the concept that most explains why you are hurt is
-inertia
One object that has twice as much mass as another object also has twice as much
-inertia
An apple weighs 1 N.The Magnitude of net force on the apple when it is in free-fall is
-1 N
A rock is thrown vertically into the air. At the top of its path, its acceleration in meters per second per second is about
-10
A 1-kg mass at the Earth's surface weighs about
-10 N
The force of friction on a sliding object is 10 N. The applied force needed to maintain a constant velocity is
-10-N
Ten seconds after starting from rest, a freely falling object will have a speed of about
-100m/s
A 1-kg rock that weighs 10N thrown straight upward at 20m/s. Neglecting air resistance, the net force that acts on it when it is half way to the top of its path is
-10N
If a freely falling object were somehow equipped with a speedometer, its speed reading would increase each second by about
-10m/s
the gain in speed each second for a freely falling object is about
-10m/s
What is the acceleration of a car that maintains a constant velocity of 100km/h for 10 s?
-10m/s/s
if you drop an object, it will accelerate downward at a rate of about m/s/s. If you instead throw it downwards, its acceleration(in the absence of air resistance) will be
-10m/s/s
a car has a mass of 1000kg and accelerates at 2m/s. What is the magnitude of the force exerted on the car?
-2000 N
the average speed of a horse that gallops a distance of 10km in a time of 30 min is
-20km/h
If a freely falling object were somehow equipped with a speedometer on a planet where the acceleration due to gravity is 20 m/s/s, then its speed reading would increase each second by
-20m/s
A car traveling at 22m/s comes to an abrupt halt in 0.1s when it hits a tree. What is the deceleration in meters per second per second of the car
-220
A girl pulls on a 10-kg wagon with a constant force of 30N. What is the wagon's acceleration in meters per second per second?
-3.0
A 2000-kg car experiences a braking force of 10,000 N and skids to a stop in 6 s. The speed of the car just before the brakes were applied was
-30m/s
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
-4000N
A skydiver, who weighs 500 N, reaches terminal velocity of 90 km/h. The aiar resistance on the diver is then
-500 N
When a woman stands at rest with two feet on a scale, the scale reads 500N. When she gently lifts one foot, the scale reads
-500 N
A person is attracted toward the center of the Earth by a 500-N gravitation force. The force of attraction of the Earth toward the person is
-500-N
A ball is thrown upwards. Neglecting air resistance, what initial upward speed does the ball need to remain in the air for a total time of 10s?
-50m/s