Transcript Newton`s Laws

Bubba has a mass of 100 kg on the earth. What is Bubba's mass on the moon where
the force of gravity is approximately 1/6-th that of Earth's?
Billie weighs 360 N on Earth. What is Billie's mass on the moon where the force of
gravity is approximately 1/6-th that of Earth's?
The amount of net force required to keep a 5-kg object moving rightward with a
constant velocity of 2 m/s is ____.
a. 0 N
b. 0.4 N
c. 2 N
d. 2.5 N
e. 5 N
f. None of the above.
Which one(s) of the following force diagrams depict an object moving to the right with
a constant speed? List all that apply.
During which time interval(s), if any, do you know there are no forces acting upon the
object? List all that apply.
During which time interval(s), if any, are the forces acting upon the object balanced?
List all that apply.
A rocket is flying toward a distant galaxy. Suddenly, the pilot realizes they are out of
fuel. The rocket will____________
a)
b)
c)
d)
arrive at the galaxy at the same speed they are moving.
arrive at the galaxy and stop.
stop before reaching the galaxy.
stop, then start moving in the opposite direction.
A 50kg box sits motionless on a ramp, as shown below.
Draw the force diagram for the box.
What is the magnitude of the normal component of the force of the ramp on the box?
20°
A 50kg box slides at 4 m/s down a ramp, as shown below.
Draw the force diagram for the box.
What is the magnitude of the normal component of the force of the ramp on the box?
v
20°
For an object resting upon a non-accelerating surface, the normal force is equal to
the weight of the object.
According to Newton's third law, every force is accompanied by an equal and
opposite reaction force. The reason that these forces do not cancel each other is
____.
a. the action force acts for a longer time period
b. the two forces are not always in the same direction
c. one of the two forces is greater than the other
d. the two forces act upon different objects; only forces on the same object can
balance each other.
e. ... nonsense! They do cancel each other. Objects accelerate because of the
presence of a third force.
As you sit in your chair and study your physics (presuming that you do), the force of
gravity acts downward upon your body. The reaction force to the force of the Earth
pulling you downward is ___.
a. the force of the chair pushing you upward
b. the force of the floor pushing your chair upward
c. the force of the Earth pushing you upward
d. the force of air molecules pushing you upwards
e. the force of your body pulling the Earth upwards
f. ... nonsense! Gravity is a field force and there is no such reaction force.
When a NASA space shuttle is flying into space, what object pushes the shuttle
forward?
a. The shuttles rockets.
b. The air behind the shuttle.
c. The earth.
d. The gas being released.
e. None of the above.
While minding your own business one day in the hallway, someone comes up to you
and slams you into the wall. Draw accurate, labeled force diagrams for each of you
during the time you are held on the wall.
List all of the objects that Block A exerts a force on.
Block A
15kg
Block B
5kg
Block C
10kg
Draw labeled force diagrams for each of the blocks.
Block A
15kg
Block B
5kg
Block C
10kg
Using g=10m/s2, attach values to each of the forces in your diagrams.
Block A
15kg
Block B
5kg
Block C
10kg
If the table were placed on a cart and rolled down the hallway, which forces would
change?
Block A
15kg
Block B
5kg
Block C
10kg
If the table were placed in an elevator moving up at a constant speed, which forces
would change?
Block A
15kg
Block B
5kg
Block C
10kg
Three pictures of equal weight (20 N) are hung by wires in three different orientations.
In which orientation are the wires least likely to break?
A car is moving toward the right. Then a force is applied causing the force diagram to
look as shown below. Draw the position vs. time graph.
Use the approximation that g=~10 m/s2 to fill in the blanks in the following diagram.
Fair on block = _______ N
FEarth on block = _______ N
m = 80 kg
a = 2.0 m/s2 down
A person pushes the block up the frictionless ramp (which makes an angle of 45 to
the horizontal). Draw a force diagram for the block.
m = 30 kg
a = 2.0 m/s2 up the ramp
A person pushes the block up the frictionless ramp (which makes an angle of 45 to
the horizontal). Use the approximation that g=~10 m/s2 to find FEarth on block.
Fperson on block
Nramp on block
FEarth on block = _______ N
m = 30 kg
a = 2.0 m/s2 up the ramp
A person pushes the block up the frictionless ramp (which makes an angle of 35 to
the horizontal). Use the approximation that g=~10 m/s2 to find Nramp on block.
Fperson on block
Nramp on block = _______ N
FEarth on block = _______ N
m = 30 kg
a = 2.0 m/s2 up the ramp
A person pushes the block up the frictionless ramp (which makes an angle of 35 to
the horizontal). Use the approximation that g=~10 m/s2 to find Fperson on block.
Fperson on block = _______ N
Nramp on block = _______ N
FEarth on block = _______ N
m = 30 kg
a = 2.0 m/s2 up the ramp