Download Forces

More Force Practice
1) What is Newton’s first law?
a) Give an example of the first law.
2) What is Newton’s second law?
a) Give an example of the second law.
b) What does the net part of net force mean?
c) Why do we always need to use and calculate the net force?
3) What is Newton’s third law?
a) Give an example of the third law.
4) Why is it important to have a correct free body diagram?
5) If a constant unbalanced force is applied the object will [ move at a constant rate /
accelerate ]
6) If a balanced force is applied the object will [ move at a constant rate / accelerate ]
7) A frictionless 10.kg wagon is pulled with 5.0N of force. Goal: find acceleration.
a) Draw a free body diagram.
b) What equations will you use to calculate?
c) Show your work.
d) The horizontal acceleration is ____________
e) What is the weight of the 10.kg wagon?___________
f) What is the magnitude of the normal force? ____________
g) Is the wagon accelerating because of gravity? [ yes / no ]
h) There will be no acceleration when the forces are [ balanced / unbalanced ]
i) Therefore, the wagon does not accelerate from gravity because:
Physics
Forces (yellow)
edited6/27/17
8) A 1000.kg car accelerates horizontally at 3.0m/s2; there is friction from the road.
a) Draw a free body diagram.
b) Sketch the acceleration graph for this motion. Sketch the related force graph.
acceleration
net force
c) How much net force is causing this acceleration?_____________
d) This acceleration is caused by the [ force of the engine / the force of friction / net
force from a combination of all the horizontal forces ]
e) If the force of friction acting on the car is 500.N what is the force from the
engine?_________
9) A football is kicked directly upward with 40.N of force. The weight of the football is
5.0N.
a) Draw a free body diagram of the ball at the moment it is being kicked.
b)
c)
d)
e)
f)
Will the ball accelerate horizontally? [ yes / no]
Will the ball accelerate vertically? [ yes / no ]
Calculate the net force on the ball. ________
What is the acceleration of the ball? _________
After the kick, when the ball is in the air, draw a free body diagram.
g) What is the net force on the ball as it moves through the air? ___________
h) What is the acceleration of the ball as it moves through the air? _________
10) An ATV weighs 2500N with a rider onboard and is rolling on flat, muddy ground at a
constant velocity. There is 900.N of friction from the mud.
a) Draw a free body diagram of the ATV.
b)
c)
d)
e)
f)
Will the ATV accelerate horizontally? [ yes / no]
Will the ATV accelerate vertically? [ yes / no ]
Calculate the net force on the ATV. ________
What is the acceleration of the ATV? _________
What is the force from the ATV’s engine?__________
g) With the same conditions, the rider accelerates at 2.0m/s/s. Draw the new free
body diagram.
h) What is the net force on the ATV now? ___________
i) What engine’s force on the ATV? _________
Physics
Forces (yellow)
edited6/27/17