Chapter 2 Test- Laws of Motion (COPY OF TEST)
The greater an object's_______, the stronger the gravitational force. (mass, speed, velocity, acceleration)
mass
The size of the force needed to produce acceleration of an object is determined by the object's______________(mass, velocity, direction, weight)
mass
Newton's first law of motion states that an object at rest stays at rest unless a________ force acts on it. (net force, balanced force, weak force, strong force)
net force
An object is pulled northward with a force of 10N and southward with a force of 15N. The magnitude of the net force on the object is (0, 5, 10, 15, none of these) N
5N
Acceleration due to gravity is______(981m/s^2, 9.81m/s, 9.81m/s^2, 0.981m/s)
9.8m/s^2
A man weighing 800 N stands at rest on two scales so that his weight is evenly distributed. The reading on each scale is (200, 400, 800, 1600, none of these) N
400N
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( < 500N, >500 N, 500N)
500N
According to Newton's second law of motion,______(F=ma, F=pv, F=mv, F=pa)
F=ma( force= mass x accleration)
Whirl a rock at the end of a string and it follows a circular path. If the string breaks, the tendency of the rock is to (continue a circular path or follow a straight-line path)
Follow a straight-line path
The force required to maintain an object at a constant velocity in free space is equal to( zero, mass of the object, the weight of the object, the force required to stop it, none)
Zero
In absence of air resistance, a penny and a feather that are dropped from the same height will__________(fall at the same rates, not have momentum, float, fall at different rates)
fall at the same rates
Every object in the universe exerts a force on every other object. This force is called____(friction, gravity, mass, inertia)
gravity
The relationship among mass, force, and acceleration is explained by______(Newton's 2nd law, Newton's 1st law, Newton's 3rd law, the conservation of momentum)
Newton's 2nd law
The statement "to every action there is an equal and opposite reaction" is_____(the law of conservation of momentum, Newton's 2nd Law, Newton's third law, Newton's 1st law)
Newton's third law
The resistance of objects to any change in motion is called____(inertia, gravity, terminal speed, acceleration)
inertia
Weight is measured in units called____(lbs, seconds, kilograms, newtons)
Newtons
Which has 0 acceleration? An object(at rest, moving at constant velocity, in mechanical equilibrium, all of these, none)
All of these
Compared with a 1-kg block of solid iron, a 2-kg block of solid iron has twice as much ( inertia, mass, volume, all, or none)
All of these- inertia, mass and volume
When an object falls through the air, its velocity increases and its acceleration (increases, decreases, remains the same)
Decreases
An object is propelled along a straight-line path by a force. If the net force were doubled, its acceleration would (quadruple, double, stay the same, halve, none of these)
Double
An elephant and a feather fall from a tree through the air to the ground below. The amt. of air resistance force is greater on the ( elephant, feather, same on both)
Elephant
A Mack truck and a Volkswagen traveling at the same speed collided head-on. The impact force is greatest on the_________(Volkswagen, Mack truck, is the same for both)
is the same for both
A car traveling at 100 km/h strikes an unfortunate bug and splatters it. The force of the impact is greater on the____(bug, car, is the same for both)
is the same for both
A real car moving at 10 km/h has more momentum than a toy car moving at the same rate because_____(its mass is greater, its mass is less, it moves faster, of friction)
its mass is greater
As a ball falls, the action force is the pull of the Earth's mass on the ball. The reaction force is the_______(air resistance acting against the ball, acceleration of the ball, pull of the ball's mass on the Earth, nonexistent in this case, none of these)
pull of the ball's mass on the Earth
An apple weighs 1N. When held at rest above your head, the net force on the apple is( 0, 0.1, 1, 10, none of these) N
0 N
A rock is thrown vertically into the air. At the top of its path, its acceleration in m/s/s is about( 0,10, between 0 and 10, >10, none of these)
10 m/s/s
Compared with the mass of a certain object on Earth, the mass of the same object on the Moon is (less, more, the same)
the same
If the same force is applied to four different objects with masses of 8 kg, 2 kg, 27 kg, 30 kg, which object will have the greater acceleration? (8 kg, 2 kg, 27 kg, 30 kg object)
2 kg object
If an object's mass is decreasing while a constant force is applied to the object, the acceleration (increases, decreases, stays the same)
Increases
A kilogram is a measure of an object's (weight, force, mass, gravity, center of mass) ?
Mass
An object maintains its state of motion because it has (mass, weight, speed, acceleration, all of these)
Mass
Strange as it may seem, it it just as hard to accelerate a car on the Moon as it is to accelerate the same car on Earth. This is because the (mass of the car is independent of gravity, weight of car is independent of gravity, nonsense ! a car is much more easily accelerated on the Moon than on the Earth)
Mass of the car is independent of gravity
Two factors that greatly affect air air resistance on falling objects are the size and ( mass of the object, weight of the object, speed of the object)
Mass of the object
When a force is exerted on an object, an equal and opposite force is exerted by the object. These forces are referred to as_________(action-reaction forces, gravitational forces, friction forces, centripetal forces)
action-reaction forces
A feather will fall through the air more slowly than a brick because of ________(air resistance, gravity, terminal velocity, momentum)
air resistance
The upward force exerted on an object falling though the air is______(terminal velocity, air resistance, weightlessness, momentum)
air resistance
A person in a head-on car collision, who isn't wearing a seat belt, continues to move forward at the same speed of the car because of________(friction, weight, gravity, inertia)
inertia
Your weight is( actually your mass, the gravitational attraction between you and the Earth, A property of mechanical equilibrium, all or none)
the gravitational attraction between you and the Earth
The measure of the force of gravity on an object is the object's____(weight, mass, friction, inertia)
weight
When a falling object has reached its terminal velocity, its acceleration is (constant, zero, g-10m/s/s)
zero
A hockey puck is set in motion across ice. If ice friction and air resistance are neglected, the force required to keep the puck sliding at constant velocity is (0 N, equal to the weight of the puck, the weight of the puck divided by the mass of the puck, the mass of the puck multiplied by 10 m/s/s, none of these)
0 N
A karate chop delivers a blow of 3000 N to a board that breaks. The force that acts on the hand during this event is actually_______(less than 3000 N, 3000 N, more than 3000 N, there is really no way to say for sure)
3000 N
If a 300 N action force is exerted to the right, the reaction force will be__________(300N to the right, 600N to the left, 300N to the left 600N to the right)
300N
If the mass of an object does not change, a constant net force on the object produces constant (velocity, acceleration, both, neither)
Acceleration
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 ( air resistance on the ball, weight of the ball, force of the ball against the bat, grip of the player's hand against the ball, none of these)
Force of the ball against the bat
A player catches a ball. Consider the action to be the impact of the ball against the player's glove. The reaction to this force is the( Player's grip on the glove, force the glove exerts on the ball, friction of the ground against the player's shoes, muscular effort in the player's arms, none of these)
Force the glove exerts
ESSAY QUESTION: IN ORDER, STATE THE THREE LAWS OF MOTION. EXPLAIN EACH LAW WITH AN EXAMPLE.
The first law motion is that an object in motion will remain in motion at a constant velocity until acted on by an outside net force; an object at rest, stays at rest until acted on by an outside net force. This can be shown by a car crash or the Pyramids of Giza. The second law is force=mass x acceleration. A football player is a good example of the second law. The third law is every force has an equal and opposite force. Hot gas pushes rocket up and rocket pushes hot gas down.
An object weighs 30N on Earth. A second object weighs 30N on the Moon. Which has the greater mass? (moon, Earth, same mass, not enough info)
The one on the Moon
Forces that are equal in size and opposite in direction are______(balanced forces, net forces, gravitational forces, frictional forces)
balanced forces
The force exerted on the tires of a car to directly accelerate it along the road is exerted by the_____(engine, tires, air, road, none of these)
road
The force needed to accelerate an object with a mass of 4 kilograms by 2 m/s^2 is_____(8 kilograms, 6 kilograms, 2 Newtons, 8 Newtons)
8 Newtons
A sheet of paper can be withdrawn from under a container of milk without toppling it if the paper is jerked quickly. The best demonstrates that ( milk carton has no acceleration, there is no action-reaction pair of forces, gravity tends to hold the milk carton secure, the milk carton has inertia, none of these)
The milk carton has inertia
A feather and a coin will have the equal accelerations when falling in a vacuum because (their velocities are the same, force of gravity is the same for each in a vacuum, the force of gravity does not act in a vacuum, the ratio of each object's weight to its mass is the same, none of these)
The ratio of each object's weights to its mass is the same
A 10-kg brick and a 1-kg book are dropped in a vacuum. The force of gravity on the 10-kg brick is ( the same as force on 1-kg book, 10 times as much, zero)
The same as the force on the 1-kg book
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 (lighter, heavier, both at the same time, not enough info)
They hit at the same time.
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____(Arnold of course, Suzie, both the same)
both the same
Which object has the greatest inertia?(pencil, toothpick, bowling ball, ping pong ball)
bowling ball
According to Newton's 2nd law of motion, the change in motion of an object is determined by the_____(inertia of the object, acceleration of the object, size of the force acting on the object, velocity acting on the object)
size of the force acting on the object
The greatest speed reached by an object falling through the air is called its_______(average speed, acceleration, inertia, terminal speed)
terminal speed
