Work, Power and EnergyHard
Question
A body of mass 5kg has momentum of 10 kg m/sec. When a force of 0.2N is applied on it for 10 sec, the change in its kinetic energy is
Options
A.4.4J
B.3.3J
C.5.5J
D.1.1J
Solution
Change in momentum,
ᐃp = F. t = 0.2 × 10 = 2
Initial value of velocity =
= 2m/sec
Initial energy =
× 5 × 2 × 2 = 10 J
Total final momentum = 10 + 2 = 12kg m/sec
final velocity =
m/sec
Final energy =
× 5 × 
×
=
= 14.4 J
ᐃp = F. t = 0.2 × 10 = 2
Initial value of velocity =
= 2m/sec Initial energy =
× 5 × 2 × 2 = 10 JTotal final momentum = 10 + 2 = 12kg m/sec
final velocity =
m/secFinal energy =
× 5 × × =
= 14.4 JCreate a free account to view solution
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