PHSC 1000 Test 2
true
The acceleration of gravity near the surface of Earth is 9.8 m/s^2.
false
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 the force on the 1-kg book.
zero
A car is moving down a freeway in a straight line at a constant rate of 24.0 m/s for 4.0 s. Its acceleration is
none of these
A constant net force acting on an object that is free to move will produce a constant
false
A hammer drives a nail into a board with a blow of 25,000 N. The reaction force that acts on the hammer during this hit is less than 25,000 N because the nail is driven into the board.
false
A space probe in remote outer space continues moving because the force acting on it is constant.
true
Compared with the mass of a certain object on Earth, the mass of the same object on the moon is identical.
false
If the mass of an object does not change, a constant net force on the object produces constant velocity.
it can be measured with any of the above referents
Velocity is measured with a referent of
3 m/s2
What is the rate of acceleration for a car that reaches a speed of thirty meters per second from rest in ten seconds?
true
When you roll a ball across the floor, it comes to a stop because a force acts on it.
m/s2
Which of the following is a possible unit of acceleration?
the acceleration is in the direction opposite the motion
Which one of the following is true for deceleration?
true
Your mass is the same no matter where you are.
list and newton's laws of motion
law 1: an object at rest will remain at rest unless acted upon by an external, unbalanced force. (car driving on cruise) law 2: F=ma (mass times acceleration)w=mg (mass times gravity) law 3: for every action there is an equal and opposite reaction. (getting pushed on skates)
Velocity
"Eighty miles per hour toward the northeast" is an example of
all of these
An acceleration may result from
zero
An automobile travels due north with a constant speed of 70 mph. All forces considered, the unbalanced force acting on the auto is
Speed
An automobile turning in a circle has a constant
turn signal
An automobile's acceleration cannot be changed by using the
changing
An object that is moving with an acceleration different from zero will always have a(n) ______________ velocity.
towards the center of the circle
An object travels in a circle of radius 10.0 m with a constant speed of 3.0 m/s. What is the direction of its acceleration?
speed
Distance covered per unit of time is called
false
Galileo believed that natural laws could be understood by logic alone.
all of these
If an object moves with constant velocity,
one-fourth as great
If the Moon were positioned twice as far from the Earth as it is now, the gravitational attraction would
the time squared
The distance traveled by a dropped object in free fall is directly proportional to
Inertia
The natural tendency of an object to remain at rest or in motion with a constant velocity is called
act on different objects
The paired forces in Newton's third law
Acceleration
The rate at which an object's velocity changes with time is called its
Displacement
The straight-line distance and direction between two points are, together, called
false
To steadily (constantly) increase the velocity of something requires an increasing force.