Forces and Motion
Another name for drag
Friction
A diagram that shows all external forces on an object.
Freebody diagram
Ep = mgh
What is the formula for potential energy ?
If a 50 N force acts on a box at rest, and friction provides a 50 N opposing force, what will happen to the box?
The box will remain at rest
A 10 N force moves an object 5 m in the direction of the force. How much work is done?
50 J
This is the measurement of acceleration
m/ss
The acceleration that points toward the center of circular motion.
Centripetal acceleration
What is the formula for kinetic energy ?
Ek = 1/2 mv2
A force of 10 N accelerates a 2 kg block across a friction-less surface. What is the block’s acceleration?
5 m/s²
Work requires at least one component of the force be ____________ to the displacement.
Parallel
Newton's three laws of motion
What are inertia, acceleration, action-reaction
These are the only two factors that affect a pendulum.
length and mass
A car travels 60 m in 4 seconds. What is its average speed?
15m/s
According to Newton’s Third Law, when you push against a wall, why doesn’t the wall move?
Because the wall exerts an equal and opposite force, but its mass and foundation prevent noticeable motion?
Hooke's Law
Stress is directly proportional to strain within proportional limit
It weighs 9.8N
1kg
Energy of motion
Kinetic Energy
Which of Newton’s laws explains why seat belts are necessary in cars?
Newton’s First Law
Because the wall exerts an equal and opposite force, but its mass and foundation prevent noticeable motion?
Friction
Units of torque
N-m
a net force of 0
Equilibrium
when considering moment at a point, forces at that point will become
Zero
What is the net force acting on a 10 kg object accelerating at 2 m/s²?
20 N
A 10 kg object is suspended by a string. What is the tension in the string if the object is at rest?
98.1 N
Unit of momentum
What is kgms-1?