Wk3 quiz 4
A 10N falling object encounters 10N of air resistance. The net force on the object is
0N
As the skydiver continues to fall faster and faster through the air,
Net force and acceleration decrease
When a space shuttle travels in a circular orbit around Earth, is force required to maintain its high speed?
No, shuttle coasts by its own inertia
The car is pushed in undergoes a certain acceleration. Consider how the acceleration would compare if it were pushed with twice the net force but it's mass increased by four. Then it's acceleration would be
One-half
And a free falling objects only a single force acts
Only a single force acts
An apple weighing 1N is held at rest above your head, the net force on the apple is zero. Why?
Support force = weight of the object
The force that allows you to walk is
The friction force of the floor on your feet And The reaction force of your foot against the floor
An object weighs 30 N on Earth. A second object weighs 30 N on the jupiter. Which has the smaller mass?
The one on Jupiter
As a ball falls, the action force is the pull of earths mass on the ball. The reaction force is
The pull of the balls mass on earth
A force of 1N accelerates a mass of 1kg at the rate of 1m/s^2. The acceleration of a mass of 2kg acted upon by a force of 2N is
The same
The newton is a unit of
Weight and force
If the mass of an object does not change, a constant net force on the object produces constant
acceleration
If an object falls with constant acceleration, the velocity of the object must
continually change by the same amount each second
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
follow a straight-line path
velocity is a ___________________ quantity
vector
A ball is set in motion across a frozen pond. Neglecting resistance, the force required to keep the ball sliding at constant velocity is
0 N
What is the magnitude of the net force on an object under free-fall? Given the mass of the object is 1kg
10N
A car has a mass of 1000 kg and accelerates at 0.2m/s^2. What is the magnitude of the force exerted on the car?
200N
The weight of 0.6 kg of steak is about
6.0 N
Which object undergoes the greatest impulse if all the baseballs have the same speed just before being caught and just after being thrown
A baseball that is caught and then thrown back.
A Mack truck and a Volkswagen traveling at the same speed have a head-on collision.
Both will exert the same force on each other, and Volkswagen undergoes the greatest change in velocity
If an object falls within constant acceleration, the velocity of the object must
Continually change by the same amount each second
Earth pulls on the moon. Similarly the moon pulls on Earth, evidence that
Earth and Moon are pulling on each other and Earth's and Moon's pulls comprise an action-reaction pair of forces.
An object is propelled along a straight line path by a force. If the net force were reduced to one-half, it's acceleration would
Halved
Due to _______ an object maintains its state of motion
Inertia
If an object follows a straight line path at a constant speed in space
It has zero acceleration
A sheet of tablecloth can be withdrawn from under a container of juice without toppling it if the tablecloth is jerked quickly. This best demonstrates
Juice container has inertia
Moon's gravity is much less than the earth's gravity; still it is just as hard to push and object on the moon as it is to push the same object on earth this is because the
Mass of the object is independent of gravity
The force exerted on the tires of a car to directly accelerate it along the road is exerted by
road
Consider a heavy and a light person jumping together with same-size parachutes from the same altitude. Who will reach the ground first?
the heavy person