Which of the following is not a simple machine?
lever, scissors, screw, wheel and axle
What is scissors
100
What are the units of work
What is joules
100
What law is explains why we use seat belts?
What is 1st law ( Inertia)
100
What is work/time
What is power
200
Which is an example of a 3rd class lever
nutcracker
hand-held boat paddle
crow bar
What is boat paddle
200
Three children exhaust themselves trying to push a large rock that doesn't budge. How much work have they done?
What is zero
200
Mass and acceleration are inversely proportional when force is constant.
F = mX a
What is Newton's 2nd Law
200
What is F X d
What is work
300
Which of the levers always has a mechanical advantage less than 1?
What is 3rd class
300
A boy pushes on a parked car with a force of 200 N. The car does not move. How much work does the boy do on the car?
What is zero
300
Mass is a measurement of somethings _____________
What is inertia
300
The brakes on a car exerta frictional force of 6000 N in getting the car to stop. If the work done by the brakes is 120,000 J in coming to a stop, how many meters did the car travel after the driver applied the brakes?
What is 20 m
400
An inclined plane
a.changes the direction of force only
b. chnges the magnitude of the force only
c. changes both direction and magnitude
What is c.
400
A weight lifter presses 400 N weight 0.5 meters over his head in 2 seconds. What is the power of the weight lifter?
What is 100 watts
400
What is the acceleration of objects in free fall on the earth?
What is 9.8 m/s/s
400
A man pushes a crate along a factory floor by exerting a force of 55 N. If the crate moves a distance of 4.0 m, how much work does the man perform?
a. 165 N b. 220 N c. zero d. 145 N
What is 220 N
500
The quantity that measures how much a machine multiplies force or distance is
What is mechanical advantage
500
An object weighing 75 N is dropped from the top of a buildig and falls a distance of 28 m to the ground. How much work does gravity do on the object.
a. zero b. 75 J c. 2100 J d. 4625 J
What is 2100
500
In the absence of air resistance, how would the acceleration of a 1.5 kg book and the acceleration of a 15 kg rock differ if they were dropped from the same height? Same or different
What is same
500
During a race , a sprinter increases from 5.0 m/s to 10.0 m/s over a period of 2 seconds. What is his acceleration during this period?