Physics Unit Test
The force required to maintain an object at a constant velocity in free space is equal to...
0
An apple weighs 1 N. When held at rest above your head, the net force on the apple is...
0N
The force of friction on a sliding object is 10 N. The applied force needed to maintain a constant velocity is...
10N and opposite
A 10N block and a 1N block lie on a horizontal frictionless table. To provide them with equal horizontal acceleration, we would have to push with...
10x as much force on the heavier block
An apple at rest weighs 1 N. The net force on the apple when it is in free fall is...
1N
A 500N parachutist opens his chute and experiences an air resistance force of 800N. The net force on the parachutist is...
300N upward
A piece of rope is pulled by 2 people in a tug-of-war. Each pulls with 400N of force. What is the tension in the rope?
400N
A person is attracted toward the center of the earth by a 500N gravitational force. The earth is attracted towards the person with a force of...
500N
A 10N falling object encounters 4N of air resistance. The net force on the object is...
6N
A block is dragged without acceleration in a straight-line path across a level surface by a force of 6 N. What is the force of friction between the block and the surface?
6N and opposite
As an object freely falls downward its...
Acceleration and velocity increases
Newton's first law(inertia) applies to...
Both moving and nonmoving objects
Suppose a particle is accelerated through space by a constant 10-N force. Suddenly the particle encounters a second force of 10-N in a direction opposite to that of the first force. The particle with both forces acting on it...
Continues at the speed it had when it encountered the second force
T/F - An astronaut weighs the same on earth as in space.
False
T/F- If you slide a hockey puck across a frictionless ice rink, there must be a horizontal force on it to keep it in motion.
False
T/F- The force due to gravity acting on an object is equal to its mass.
False
T/F- A bicycle and a parked car have a head-on collision. The force of impact is greater on the bicycle.
False- they are the same
What causes a change in an objects motion?
Force (push/pull)
An object is propelled along a straight-line path in space by a force. If the mass of the object somehow becomes twice as much, it's acceleration
Halves
A skydiver's terminal velocity will be greatest if she falls...
Head first
If an object's mass is decreasing while a constant force is applied to the object, the acceleration...
Increases
If your auto mobile runs out of fuel while you are driving the engine stops but you do not come to an abrupt stop. The concept that most explains why is...
Inertia
Whenever the net force on an object is zero, it's acceleration...
Is zero (means constant velocity)
An objects weight may properly be expressed in units of...
Newtons
A carpenter hits a nail with a hammer. During the collision there is a force...
On the nail and also on the hammer
A force is a vector quantity because it has both
Size and direction (magnitude= size)
Compared to the mass of a certain object on earth, the mass of the same object on the moon is...
The same
A car traveling at 100 km/hr strikes an unfortunate bug and splatters it. The force of impact is...
The same for both
A semi truck and a Volkswagen traveling at the same speed collide head-on. The impact force is...
The same for both
A horse exerts 500 N of force on a heavy wagon. The wagon pulls back on the horse with an equal force. The wagon still accelerates because...
The wagon does not accelerate because these forces are equal and opposite
The earth pulls on the moon. Similarly the moon pulls on the earth, evidence that...
These two pulls compromise an action-reaction pair
A tennis ball and solid steel ball the same size are dropped at the same time. Which ball has the greater force acting on it?
They both have the same force acting on them
T/F- The combination of all the forces that act on an object is called the net force.
True
A semi truck and a Volkswagen traveling at the same speed have a head on collision. The vehicle that undergoes the greatest change in velocity will be the...
Volkswagen
If the mass of an object does not change, a constant net force on the object produces constant...
acceleration
An archer shoots an arrow. Consider the action force to be exerted by the bowstring against the arrow. The reaction to this force is the...
arrow's push against the bowstring
If no external forces are acting on a moving object, it will
continue moving at the same velocity
A truck is moving at a 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 Newton is a unit of...
force
An object following a straight-line path at constant speed...
has zero acceleration
If one object has twice as much mass as another object, it also has twice as much
inertia
Wherever there is an action force, there must be a reaction force which...
is exactly equal in magnitude (action=reaction)
A kilogram is a measure of an object's
mass
When a rocket ship accelerating in outer space runs out of fuel it
no longer accelerates
A skydiver falls towards the Earth. The attraction of the Earth on the diver pulls the diver down. What is the reaction to this force?
none of these
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 attraction of a person's body toward Earth is called weight. The reaction to this force is
the person's body pulling on the Earth
An object is propelled along a straight-line path by a force. If the net force were doubled, the object's acceleration would be...
twice as much
After a cannonball is fired into frictionless space, the amount of force needed to keep it going equals...
zero, since no force is necessary to keep it moving (inertia is NOT a force)