Download Final Exam Study Guide

Final Exam Study Guide
January 2009
You are authorized to have a 3x5 card for the Final Exam. You may only use a handwritten 3x5 card. You will turn it in after the Exam. The Final Exam is 60 questions and
you will have 90 minutes. There are no retakes for the Final Exam.
Speed = Distance divided by time. If distance = zero, then speed = 0.
Use the triangle of science for the speed formula. Put the distance on top.
SI units are m/s.
Velocity is speed with a direction. That makes it a vector.
Acceleration = Change in Velocity divided by time. Acceleration is also a vector.
If acceleration is negative, you are slowing down. SI units are m/s2.
You can use the triangle of science for acceleration, too.
Put change in velocity in the top.
Acceleration due to gravity (g) is always 9.8 m/s2 near Earth’s surface. This is the
object’s free fall acceleration. If it continued to free fall it would reach terminal
velocity, where the force of the air resistance equals the force of gravity.
All objects fall at the same rate (that 9.8m/s2 number), regardless of mass. This is true if
we ignore (or negate) air resistance. The hammer and feather hit the moon at the same
time when dropped by Apollo 17 astronauts.
A force is a push or a pull one body exerts on another body.
Force = mass times acceleration. Force is a vector, too.
Put the F in the top of the triangle. Force is measured in Newtons (N).
When we insert g for the acceleration we can find the weight of a known mass.
W = m x g. Put the W in the top of the triangle.
A projectile follows a curved path. It is anything shot or thrown through the air.
Momentum is mass times velocity. We use p for the momentum. Put p in the top of the
triangle. Momentum is measured in kg●m/s.
Impulse is change in momentum. We didn’t discuss impulse this semester.
Work = Force x Distance. Work, like energy, is measured in Joules. Put W in the top of
the triangle.
Kinetic energy is the energy due to an object’s motion. KE = ½ mv2.
Potential energy is the energy due to an object’s position {GPE}.
GPE = mgh
Mechanical energy is the KE + PE of an object.
Elastic potential energy is stored in springs or compressed things.
Power = Work/time or Energy/time. Power is known as a rate at which energy is
transferred.
Gravity is affected by the Inverse Square Law. So, if you double the distance you
quarter (one-fourth-ify) the amount of gravity. If you triple the distance the force due to
gravity is one-ninth the original.
Also, gravitational force depends on the masses of the objects and the distance between
them.
F = (Gm1m2)/d2, with G being the Universal Gravitational Constant 6.67 x 10-11 Nm2/kg2
Where m1 and m2 are the two masses and d is the distance in meters.