45 terms

# Conceptual physics 105 exam #1-science, newton's laws and motion

#### Terms in this set (...)

An educated scientific guess is a
Hypothesis
For a scientific hypothesis to be valid, there must be a test for proving it
Wrong
Inertia is defined as a
Property of matter
If no external forces act on a moving object, it will
Continue moving at the same speed
A force is a vector quantity because it has both
Magnitude and direction
A block pulled to the left with 15N and to the right with 5N at the same time experiences a net force of
10N
An object in mechanical equilibrium is an object
At rest, moving with constant velocity and having no changes in velocity
Burl and Paul have a total weight of 1300N. The tensions in the supporting ropes that support their scaffold add to 1700N. The weight of the scaffold itself must be
400N
The net force on any object in equilibrium is
zero
The support force on a 10N book at rest on a table is
10 N
An 800-N man stands at rest on two bathroom scales so that his weight is distributed evenly over both scales. The reading on each scale is
400 N
Earth continually moves about 30 km/s through space, which means the wall you stand next to also is moving at 30 km/s. When you jump vertically the wall doesn't slam into you because
You're moving horizontally just as fast as the wall
The newton is a unit of
Force
A kilogram is a measure of an object's
Mass
1-kg mass at the Earth's surface weighs
10 N
Compared to the mass of an apple on Earth, the mass of the apple on the Moon is
The same
The speedometer of an automobile reads
instantaneous speed
The two measurements necessary for calculating average speed are
Distance and time
When you walk at an average speed of 4 m/s, in 5 s you'll cover a distance of
20 m
A freely-falling watermelon falls with constant
acceleration
The distance a freely falling bowling ball falls each second
increases
The force of friction on a sliding object is 10 N . The applied force needed to maintain a constant velocity is
10 N
A 10-N falling object encounters 4 N of air resistance. The net force on the object is
6 N
If the mass of a cart is quickly loaded to have twice the mass while a propelling force remains constant, the cart's acceleration
Halves
A heavy block at rest is suspended by a vertical rope. When the block accelerates upward by the rope, the rope tension
Is greater than its weight
A car has a mass of 1000kg and accelerates at 2 m/s^2. What net force is exerted on the car?
2000N
Neglecting friction, a small and a large block of ice begin sliding down an incline together. The larger block reaches the bottom
At the same time as the small block
When a falling object has reached its terminal velocity, it's acceleration is
Zero
A light woman and a heavy man jump from an airplane at the same time and open their same-size parachutes at the same time. Which person will get to the ground first?
The heavy man
A skydiver's terminal velocity will be greatest if she falls
A 500-N parachutist opens his chute and experiences an air resistance force of 800 N. The net force on the parachutist is then
300 N upward
According to Newton, the greater the masses of interacting objects, the
greater the gravitational force between them
According to Newton, when the distance between two interacting objects doubles, the gravitational force is
One-quarter
In comparison with other fundamental forces, the universal gravitational constant G indicates that gravity is
very weak
If the Sun collapsed to a black hole, Earth's gravitational attraction to it would be
the same
Accelerate an electron and you produce an electromagnetic wave. Accelerate a massive body and you produce
a gravitational wave
Einstein's theory of gravitation
Agrees with established results of Newton's theory, incorporates Newton's theory as a special case, has been supported by repeated experiments, and is superior to newton's where space time is more curved.
You cannot exert a force on a wall
unless the wall simultaneously exerts the same amount of force on you
The winner in a tug-of-war exerts the greatest force on
The ground
A pair of action-reaction forces always
occur simultaneously
For every action force, there must be a reaction force that
is equal in magnitude
A player hits a ball with a bat. If action is the force of the bat against the ball, reaction is the
force that the ball exerts on the bat
Joshua is attracted toward Earth by a 500-N gravitational force. The Earth is attracted toward Joshua with a force of
500-N
The force that propels a cannonball when fired from a cannon is
equal and opposite to the force the ball exerts on the cannon
When a cannonball is fired from a cannon, which undergoes the greater acceleration?
the cannonball