TS EAMCET 6-Aug-2021 Shift 2 Question Paper

Mass of the body, m=15kg
The instantaneous power due to the force F at the end of 3s,P=5W.
Acceleration, a=‌

F

m

From kinematics, v=u+at
⇒‌v‌‌=at(∵u=0)
⇒‌‌v‌‌=‌

F

m

t‌
‌‌=‌

3F

m

(∵t=3s)
‌∵‌ Power ‌=5W=F⋅v=‌

3F2

m

⇒‌‌F2=‌

5m

3

=‌

5×15

3

=25⇒F=5N
Let the instantaneous power at the end of 4 th second be P1 and velocity of body at the end of 4s be v′, then
v′‌‌=u+at=0+‌

F

m

t
v′‌‌=‌

5

15

×4=‌

4

3

m∕s‌‌(∵t=4s)
P1‌‌=F⋅v′
‌‌=5×‌

4

3

=‌

20

3

W=6.67W