# WHITE BOARD TIME !! Work Changes KE ```WHITE BOARD TIME !!
Work Changes KE
A 4 kg bowling ball is rolling down the hallway with
an initial speed of 2 m/s. Gaby exerts a constant
force through a displacement of 0.4 m. The force
exerted by Gaby does
-0.6 J of work (assume no
force of friction). What’s the final velocity of the
ball?
1.List all physical quantities.
m=
F=
m=
vi =
Dd =
vF =
KEi =
W=
KEF =
2.Write the work-energy theorem relationship.
Solve for velocity.
3.Make a bar chart of KEi + W = KEF
A 0.05 kg bullet traveling at 200 m/s hits a
post 0.5 m thick. The bullet comes out on
the other side of the post with a speed of
120 m/s.
1.List all physical quantities.
m=
F=
m=
vi =
Dd =
vF =
KEi =
W=
KEF =
2.Write the work-energy theorem relationship.
Solve for the force exerted by the post on the
bullet.
3.Make a bar chart of KEi + W = KEF
Holly exerts a constant force of 12 N at 60&ordm;
above the horizontal on a 6.4 kg sled.
Assume the sled starts at 0.5 m/s and
slides horizontally through a displacement
of 2 m. (assume no force of friction).
1.List all physical quantities.
m=
F=
m=
vi =
Dd =
vF =
KEi =
W=
KEF =
2.Write the work-energy theorem relationship.
Solve for the force exerted by the post on the
bullet.
3.Make a bar chart of KEi + W = KEF
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