Net Force, Acceleration and Mass Date ______
When two objects are in contact, the magnitude of the force exerted on object 1 by object 2 is ________________ to the magnitude of the force SIMULTANEOUSLY exerted on object 2 by object 1. These forces are _______________ on direction.
The acceleration of the object depends on the ________ _____________ on the object and the _______________ of the object.
The acceleration of an object is ______________ proportional to the net force acting on the object.
The acceleration of an object is ______________ proportional to the object's mass.
If equal forces are applied to two objects of different masses, the object with less mass will experience a _______________ acceleration and the object with more mass will experience a _________________ acceleration.
1
Net force = ____
NO ________
in motion.
2
This relationship can be written in equation form.
a = Fnet
or
Fnet = ma where Fnet is a vector sum of all the forces on an
m object. It call the net force.
Net Force(N) Mass (kg)
Acceleration
(m/s2 )
1.
10
2
2.
20
2
3.
20
4
4.
5.
2
10
5
10
When the mass is constant and the net force is doubled, the acceleration __________
When the net force is constant and the mass doubles, the acceleration ____________
3
Two identical spring loaded dart guns are
simultaneously fired straight downward.
One fires a regular dart; the other a weighted
dart. Which dart hits the ground first?
Why?
4
You have a 10 N bar of gold on Jupiter where the acceleration due to gravity is
­25.0 m/s2. You have another 10 N bar of gold on the
Earth where the acceleration due to gravity is
­9.8 m/s2.
Which has the greater mass? 5
In Chapter 2 acceleration was the rate of change of velocity: a = vf ­ vi
Δt
In Chapter 4 acceleration is the ratio of the net force to mass: a = Fnet
m
Which is it?
The ratio of force to mass (a = F/m) which is the cause of the acceleration determines the rate of Acceleration is defined as the rate of change of velocity, but it is produced by a net force.
change of velocity (a = (v
f ­ vi)/Δt).
Acceleration is defined as the _______________________________________, but it is produced a _______________________.
The ratio of force to mass __________________ which is the ________________ of the acceleration determines the rate of change of __________________________
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Net Force, Acceleration, and Mass Practice Problems:
Two people with the same mass of 50 kg are riding in a pickup truck at 20 m/s.
They are brought to an abrupt stop in a head on collision with a drunk driver who has crossed the divider line.
One person wears a seat belt and is brought to a stop in 0.1 second.
The other person is not wearing a seat belt and is brought to a stop by the dashboard in 0.01 seconds.
1) What is the deceleration of the person who comes to a stop wearing the seat belt?
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2) What is the net force exerted by the seat belt to bring the first person to a stop?
3) What is the deceleration of the person who comes to a stop by hitting the dashboard?
4) What is the net force exerted by the dashboard to bring the second person to a stop?
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