Download Name

Name_____________________
Newton’s 2nd Law WS
date____
1. The diagrams below show the forces acting on a pilgrim (the dot) of mass 75 kg for 3 cases.
40 N
A
22 N
22 N
350 N
B
C
50 N
260 N
260 N
40 N
34 N
350 N
a/ Find the net force, Fnet, for each case.
b/ Which diagram above is for a pilgrim at rest?
c/ Which diagram above is for a pilgrim moving with constant velocity?
d/ Which diagram is for a pilgrim in equilibrium?
e/ Which diagram above is for a pilgrim that is accelerating?
In what direction is he accelerating?
2. The net force acting on a cauldron is 150 N, east. If the cauldron accelerates at 3.5 m/s2, what is its mass?
3.
The forces at right act on a turkey of mass 2.5 kg.
5.0 N
a/ Find the acceleration of the turkey.
50 N
50 N
b/ If the initial velocity of the turkey is 4.0 m/s north, what distance will it travel in 3.0 s?
c/ Sketch a vs. t and v vs. t
for the 3.0 s.
a
v
1
2
3
t
d/ What is the slope (number plus units) of the v vs. t graph?
e/ What quantity does the slope of v vs. t represent?
f/ What is the area (number plus units) under the line of the v vs. t graph?
g/ What quantity does the area under the line of the v vs. t graph represent?
4.
What net force is necessary to accelerate a 0.37 kg basketball at 8.5 m/s2?
1
2
3
t
5. The forces shown at right act on a 55-kg soccer player.
What will be the acceleration of the soccer player that results?
250 N
120 N
380 N
250 N
6. A net force of F applied to a broomstick of mass m causes an acceleration a. What would be the new
acceleration if the…
a/ …applied force were changed to 2F?
If it were changed to 3F?
b/ …same force were applied to a broomstick of mass 2m?
To a broomstick of mass 3m?
c/
…applied force were changed to 2F and this new force was applied to a broomstick of mass 2m?
d/
…applied force were changed to 5F and this new force was applied to a broomstick of mass 3m?
7. A 0.25-kg plastic pumpkin is being pulled across a frozen pond with a force of 5.0 N to the right.
a/ Draw a force diagram and label the name and
magnitude of all the forces that act on the pumpkin.
Use g = 10. m/s2 and assume no friction.
scale: 1 cm: 2.5 N
b/ What is the net force acting on the plastic pumpkin?
c/ What is its acceleration?
d/ If there were a constant frictional force of 2.0 N, what would be the new Fnet and acceleration?
e/ If there were a constant frictional force of 5.0 N, what would be the new Fnet and acceleration?
8. An 8.0-kg sled is being dragged horizontally across the snow by a force F = 50 N that makes an angle  =
300 to the horizontal. Use g = 10. m/s2 and assume no friction.
a/ Sketch the forces aside from F that act on the sled.
(No scale needed—just sketch and label.)
300
b/ Determine the x- and y-components of F:
Fx =
Fy =
c/ Why must the up vertical forces balance the down vertical forces?
Use that fact to determine FN.
d/
Which component of F is unbalanced and causes the sled to accelerate?
e/
What is the acceleration of the sled?
f/ What would happen to the acceleration if  were increased?
What would happen to the FN?
Explain.
Explain.
F=
50 N