Newton’s Laws of Motion
N2L Practice
Name: ______________________ Date: ___________
Due: Wed, Feb 6 2019
1. Consider the following scenario:
y
x
A block is initially at rest on a
horizontal surface.
A hand pushes horizontally so that the
block reaches the desired speed, vmax.
The hand is removed and the block
slows to rest.
The block’s velocity along the x-direction is given qualitatively by the graph below. Sketch qualitatively-correct
and consistent free-body diagrams and force addition diagrams for times t1 through t4 below.
t1
FBD
t2
FAD
FBD
FAD
FBD
t3
FBD
FAD
t4
FAD
2. A curling stone of mass 18 kilograms is observed to slow down from a speed of 4.5 m/s to a speed of 1.5 m/s
during a time interval of 7.5 seconds. Determine the magnitude of the net force on the stone.
Physics
-1-
Mr. Almeida
3. A 4.0 kg bucket of grease is being pulled upward by a cord.
(a) Which is greater, the gravitational force or the tension force if the bucket is …
iii.
___ gravitational
___ tension
…ascending and speeding up
iv.
___ gravitational
___ tension
…rising and slowing down
v.
___ gravitational
___ tension
…descending and speeding up
vi.
___ gravitational
___ tension
…descending and slowing down
(b) Find the tension in the cord if the bucket is accelerating upward at 2.4 m/s2.
4. A football coach sits on a sled while two of his players build their strength by dragging the sled across the
field with ropes. The friction force on the sled is 1200 N and the angle between the two ropes is 22°. How
hard must each player pull to drag the coach at a steady 2.0 m/s?
5. You push a 1.60 kg box along a surface that is inclined at 25.0° such that the box accelerates upward along
the incline at 0.5 m/s2 along the incline. The friction between the box and incline is negligible. Find the
magnitudes of the individual forces acting on the box.
Physics
-2-
Mr. Almeida