Science exam
A hockey puck is set in motion across a frozen pond. If ice friction and air resistance are neglected, the force required to keep the puck sliding at constant velocity is
0
Two identical freight cars roll without friction towards each other on a level track. One car rolls at 2 m/s and the other car rolls at 1 m/s. After the cars collide, they couple and roll together with a speed of
0.5 m/s
The mass of a pet turtle that weighs 10N is about
1 kg
A man weighing 800 N stands at rest on two bathroom scales so that his weight is distributed evenly over both scales. The reading on each scale is
400
A piece of rope is pulled by two people in a tug-of-war. Each pulls with 400 N of force. What is the tension in the rope?
400
The attraction of a person's body towards the Earth is called weight. The reason to this force is
The persons body pulling on the earth
When you stand at rest on a pair of bathroom scales, the readings on the scales will always
add to equal your 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 an isolated piece of tissue paper with his best punch. You
agree that it can't be done.
A force is a vector quantity because it has both
magnitude and direction
The force exerted on the tires of a car to directly accelerate it along a road is exerted by the
road
An object weighs 30 N on Earth. A second object weighs 30 N on the moon. Which has the greater mass?
the one on the moon
A push on a 1 kg brick accelerates the brick. Neglecting friction, to equally accelerate a 10 kg brick, one would have to push with
10 times as much force
A 500-N parachutist opens his chute and experiences an air resistance force of 800 N. The net force on the parachutist is
300 N upward
A 300-kg bear grasping a vertical tree slides down at constant velocity. The friction force between the tree and the bear is
3000
A person is attracted toward the center of Earth by a 500-N gravitational force. The Earth is attracted toward the person with a force of
500 N
A 30-kg girl and a 25-kg boy face each other on friction-free roller blades. The girl pushes the boy, who moves away at a speed of 1.0 m/s. The girl's speed is
8.3 m/s
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
It is correct to say that impulse is equal to
change in momentum
Compared with the force that brings a small car to a stop, the force required to bring a heavy truck traveling at the same speed to a stop
depends on the time involved
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 it's handle hits a solid surface so 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
If an object's mass is decreasing while a constant force is applied to the object, the acceleration
increases
Whenever the net force on an object is zero, its motion change
is zero
A rock is thrown vertically into the air. At the very top of its trajectory the net force on it is
its weight
