a hammer
lever
stored energy
potential energy
In 0.56 seconds a rolling marble traveled 20.0 cm. What’s its average speed?
35.7 cm/sec
What is the formula to calculate speed?
distance divided by time
force
flagpole
pulley
Keeps planets in their orbit, pulls things down
gravity
If a car travels 300 miles in 5 hours, what is the speed of the car?
60miles/hour
60 mph
speed in a given direction is called
velocity
Where does the roller coaster have the MOST potential energy?
A
lightbulb
screw
speed up, slow down or change direction
acceleration
What is the net force?
50N
When a student pushes a desk across the floor she can feel a force that is resisting the motion of the desk. What is the force?
a) gravity
b) friction
friction between the desk and the floor
A person has more kinetic energy when he is _____________
a) running down a hill
b) sleeping
c) standing still
d) sitting
running down a hill
doorknob
wheel and axle
velocity
If a boat traveled 400 km. in 5 hours, its average speed would have been
80km/hour
Does your weight change on the moon?
yes! Your mass stays the same
The faster something is going or the more it weighs, the more mass it has, the more __________ it has.
momentum
axe
wedge
This force slows things down and opposes motion
friction
If a runner ran a 50 meter-dash in 5.0 secs his average speed would have been ______
10m/sec
balanced or unbalanced?
balanced
A slide is an example of what simple machine?
inclined plane