Unit 4 Midterm Review
Bradley Sposit
Key Concepts of Unit 4
- Force body diagrams- You need to know how to explain and draw them.
- Describe the relationship between net force, mass, and acceleration.
- Calculate the net force, mass, or acceleration of an object.
- Explain the difference between mass and weight given a changing gravitational field.
- Evaluate and develop a mathematical model for elastic (spring) forces.
- Predict the force required to slide an object relating to the coefficient of friction.
- NEWTONS SECOND LAW!!!!!
Formulas
- Fnet = m*a
- a = Δv / Δt
- Δx= ½ at^2 (if v0 = 0)
- Fc = mv^2 / r
- ac = v^2 / r
- Felastic = k Δx
- v1^2 = v0^2 + 2a (Δx)
- Fk = μk*FN
Vocabulary
Circular- A circle shape
Centripetal- Think of the "bucket and rope" trick
Centrifugal- is the effect that tends to move an object away from the center of a circle it is rotating about
Free-body diagram- The arrow diagram that shows forces on a object
Friction- The force resisting the relative motion of solid surfaces
Kinetic- Resistance to objects in motion
Static- Stationary friction
Linear- A direct relationship (straight line)
Normal force- The force that is perpendicular to the surface
Net force- The overall force acting on an object
Tangent- Opposite divided by adjacent
Torque- A measure of force acting on an object that causes it to rotate
Weight- Mass*Gravity
Apparent Weight- force exerted on a scale
Weightlessness- Apparent weight is zero
Practice Questions
Question #1
Question #2
Question #3
a) What is the velocity of the current?
b) What is your speed relative to the water?