Question

The distance X moved by a body of mass 0.51
under the action of a force varies with time ti
x(m) = 3t2 + 4t + 5 (here t is expresed in second
What is the work done by the force in fir
2 seconds?
(1) 20 J
(2) 40J
(3) 50 J
(4) 60 J​

Answer 1

Answer:

60 J

Explanation:

x(m) = 3t2 + 4t + 5

dx/dt = v = 6t +4

dv/dt = a = 6

Now,

x(0) = 5

x (2) = 3(4)+4(2)+5 = 25

So, dx = 25-5 = 20

Work = F.x =(m.a)(dx)= (0.5x6)(20)

= 60 J

Answer 2

Answer:

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