In order for a tennis serve to have the maximum speed, the
server needs and big force and a long _______________

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Momentum Word Problems

J = Ft = mΔv = Δp

Ex 1) A 5.0 kg mass has its
velocity change from 8.0 m/s east to 2.0 m/s east.

Find the objects change in momentum.

Ex 1) A
5.0 kg mass has its velocity change from
8.0 m/s east to 2.0 m/s east.
Find the objects change in momentum.

m = 5.0 kg
V_{i} = 8.0 m/s East
V_{f} = 2.0 m/s East
Δp = ?

J = Ft = mΔv =Δp

Δp = mΔV

= (5.0 kg)(2.0 m/s - 8.0 m/s)

= -30. kgm/s East

or +30. kg m/s West

Ex 2) A 5.0 kg mass moving
with a velocity of 8.0 m/s east has an impulse applied to it
which causes its velocity to change to 20. m/s East.
Find Impulse:

Ex 2) A 5.0
kg mass moving with a vector of 8.0 m/s
east has an impulse applied to it which causes its velocity to
change to 20. m/s East.

Find Impulse:

m = 5.0 kg
V_{i} = 8.0 m/s East
V_{f }= 20. m/s East
J = ?

J = Ft = mΔv =Δp

J = mΔv = (5.0 kg)(12. m/s
East)

= 60. kg m/s east

= 60. Ns East

Find the force if the impulse was applied for
3.0 sec.