Forces
A force is a ______________
push or pull
The force that one surface exerts on another when the two rub against each other is called
friction
acceleration due to gravity is
9.8 m/s2 (10)
What is the force of a 4 kg object accelerating a 2 m/s2
8 N
Billy pulls right with 5 N of force. Tom pulls left with 5 N of force. What is the net force?
0
When solid surfaces slide over each other that is
sliding friction
If you go skydiving,what will be your velocity by 2 seconds after you jump from the plane?
19.6 m/s (20)
What is the momentum of a 4 kg object traveling at 10 m/s
40 kg m /s
This is the tendency of an object to resist change in its motion
Inertia
When an object rolls over surface that is called
rolling friction
A projectile is shot from the same height as an identical object is drop. Both objects are dropped at the same time. Which will hit the ground first?
SAME TIME
An object weighing 2 kg has 18 N of force applied to it. What is its acceleration?
9 m/s
State Newtons first law
an object at rest will stay at rest and an object in motion will stay in motion unless acted upon by an unbalanced force
Putting grease on gear is an example of how to take advantage of which type of friction
fluid
what is the equation for weight
w=m x acceleration due to gravity
you drop an object from a plane. How far has it gone after 2 seconds?
20 m
what is the equation for newtons second law
F = ma
What two factors affect friction
type of surface and how hard the surface is
What is the weight of a 3 kg object
29.4 N (30)
Joe is running 5 m/s. He weights 50 kg. How fast does tommy need to run to have enough momentum to stop joe if he weights 40 kg?
6.25 m/s