Physical Science Chapter 12
Express the following as an equation: One newton is the force that can give an object with a mass of 1 kg an acceleration of 1 m/s2.
1 N = 1 kg x 1 m/s^2
One newton is the force that can give a mass of 1 kg an acceleration of
1 m/s^2.
What unbalanced force is needed to give a 976 kg vehicle an acceleration of 2.50 m/s^2?
2.44 x 10^3 N
What is the momentum of a 255 g apple falling at 16.0 m/s?
4.08 kg x m/s downward
Calculate the velocity of a 90.5 kg man running south with a momentum of 389 kg • m/s.
4.30 m/s south
A 0.25 kg steel ball experiences a net force of 1.15 N as it rolls down a ramp. What is the acceleration of the ball?
4.6 m/s^2
How much does a 59.0 kg woman weigh on Earth?
578 N
A force of 240.0 N causes an object to accelerate at 3.2 m/s^2. What is the mass of the object?
75 kg
What happens immediately after a sky diver opens her parachute?
Air resistance greatly increases.
Two identical cars are traveling at equal speeds. One is going north and the other south. If they collide head-on and stick together, what will happen to the motion of the cars?
Both cars will stop.
How does the total momentum of two objects before a collision compare with the total momentum after the collision?
It is the same.
The law that states that every object maintains constant velocity unless acted on by an unbalanced force is
Newton's first law of motion.
The law that states that the unbalanced force acting on an object equals the objects mass times its acceleration is
Newton's second law of motion.
Earth pulls on the moon and holds the moon in its orbit. The moon pulls on Earth with an equal and opposite reaction. This is an example of
Newton's third law.
What results in the greatest acceleration?
The most force and least mass
Which statement about action-reaction force pairs is incorrect: they act on the same object, they always occur in pairs, they occur at the same time, or they are equal and opposite?
They act on the same object.
In the absence of air resistance, how would the acceleration of a 1.5 kg book and the acceleration of a 15 kg rock differ if the objects were dropped from the same height?
They would not differ; they would be the same.
Which object has the greatest inertia out of these options: a tennis ball, a bowling ball, a beach ball, or a volleyball?
a bowling ball
Which is an example of projectile motion: a rolling bowling ball, a dart thrown at a dart board, a balloon rising in the air, or a high-speed train accelerating?
a dart thrown at a dart board
The gravitational force between two objects depends on masses of objects and
distance between objects.
Whenever a force is exerted, another force occurs that is _____ in size, and _____ in direction.
equal, opposite
When the velocity of an object changes, it is acted upon by a(n)
force.
Orbital motion is a combination of
forward motion and free fall.
What force causes a skater sliding on the ice to gradually slow down?
friction
When an object is in free fall, the only force acting on it is
gravity.
Astronauts "float" when inside an orbiting spaceship because they are
in free fall.
The tendency of an object at rest to remain at rest is
inertia.
Free-fall acceleration near Earth's surface
is the same for all objects.
What unit is used to measure acceleration?
m/s^2
Increasing which of these conditions results in more gravitational force between two objects: distance, acceleration, mass, or surface area?
mass
An object's momentum is determined by the object's
mass and velocity.
Near Earth's surface, an object's free-fall acceleration does not increase as its
mass, weight, and/or speed increases.
The SI unit of force, named after the scientist who described the relationship between motion and force, is called the
newton.
What has a momentum of zero?
something that is not moving, for example a newspaper lying on a table
When gravitational forces and air resistance equalize on an object that is falling toward Earth and the object stops accelerating, what is the velocity of an object called?
terminal velocity
Weight is best described as
the downward force exerted on an object due to gravity.
If two objects with different masses and traveling with different velocities collide, what law allows you to predict the motion of the objects after the collision?
the law of conservation of momentum
The greatest gravitational force would occur between
the moon and Earth.
A seat belt helps you when your car stops suddenly by providing a(n)
unbalanced backward force.
What is the equation for weight?
w=mg