Question

6.4kJ of energy causes a displacement of 64m in a body in the direction of force in 2.5s.Calculate
1.The force applied.
2.Power in HP.
Take 1 HP = 746W

Answer 1

@Abhisar @TorilovesVampires

Answer 2

W = K.E = 6.4 kJ = 6.4 x 103 J
W = F.d. cos θ
Now the displacement of the body is in the direction of applied force.
θ = 0
W = F.d
F = W/d = (6.4 x 103 J)/64 m
F = 100 N
Power P = W/t
= (6.4 x 103 J)/(2.5)
=16 x 103 W
=1.6 x 104 W
= (1.6 x 104) / 746
= 0.0021 x 104 H.P.
Power P = 21 H.P.

Answer 3

???

Answer 4

Yo, wassup?

Answer 5

I'm confused.
Shouldn't the F be 10.3?

Answer 6

Work = Force x Displacement and this work done will be equal to energy supplied, Right?

Answer 7

Yes.

Answer 8

Let the applied force be F, then

6400 = F x 64. Now you can calculate the force.

Answer 9

100N

Answer 10

You got it ;)

Answer 11

And the P?

Answer 12

\(\sf Power = \frac{Work/Energy}{Time}\)

You know the work, you know the time. Just plug in the values and find power.

Answer 13

64000/25?

Answer 14

2560 W?

Answer 15

6.4 KJ = 6400 J

Answer 16

Power = 6400/25

Answer 17

Time is 2.5 s not 25s

Answer 18

Right, then it's correct!

Answer 19

Finally, convert the power into HP. 1 HP =746 Watts.

Answer 20

3.43?

Answer 21

That's right!

Answer 22

Thanks @Abhisar and @TorilovesVampires both.

Answer 23

pleasure is all mine c: