Vocabulary
A force that resists the motion of objects or surfaces as they move over one another is called ___________.
friction
Give an example of friction.
TRUE or FALSE: A Force is the ability to change motion.
true!
What is the formula for finding weight?
F = MG
According to legend, Galileo dropped two balls from the Tower of Pisa to see which would fall faster. Suppose one of the balls had a mass of 5.0 kilograms. Given the acceleration of gravity is 9.8 m/sec2, what was the weight of the ball in newtons?
49 newtons
The metric unit of force required for a 1-kg object to accelerate at 1 m/s2 is the ____________.
hint: the unit scientists prefer
Newton
What does a maglev train use to reduce friction?
a) oil
b) air cushion
c) ball bearings
d) water
air cushion
TRUE or FALSE: Tension is a contact force.
true!
On the surface of Earth, the value for the force of gravity is ______.
A diagram shows all the forces acting on an object is a ____________ diagram.
free-body diagram
The tires on a car have grooves in them. How do these grooves affect the friction between the tires and the road during wet weather?
a) increase friction
b) decrease friction
c) have no effect on friction
increase friction
TRUE or FALSE: Oils and other lubricants totally eliminate friction.
false!
it does not totally eliminate the friction, just reduces it
A vector, such as force, can be represented by drawing an arrow. The length of the arrow indicates the ___________ of the force.
strength
When the forces on an object are balanced, we say that the object is in _________________.
equilibrium
*see picture*
Due to the forces acting on the airplane, will the airplane speed up, slow down, or maintain its speed?
slows down
TRUE or FALSE: If you traveled to Mars, your mass would be different than your mass on Earth.
False!
Your mass stays the same.
If the net force on a moving object is zero, what happens to its speed and direction?
the speed and direction will not change.
The force exerted by a surface on an object that is pressing on it is the ____________ force.
normal
Give an example of an object that is in equilibrium.
examples could be
A box resting on a table without moving
A box at a constant speed of 5 cm/s
TRUE or FALSE: A zero net force causes an acceleration.
false!
Which of the following forces is a contact force?
a) friction
b) gravity
c) magnetism
d) electricity
friction