Question

The distance x moved by a body of mass 0.5 kg under the action of a force varies with time T as x(m)=3t²+4t+5 (here t is expresed in second). what is the work done by the force in first 2 second ?
a) 20 J
b) 40 J
c) 50 J
d) 60 J​

Answer 1

Answer:

The distance x moved by a body of mass 0.5 kg under the action of a force varies with time T as x(m)=3t²+4t+5 (here t is expresed in second). what is the work done by the force in first 2 second ?

a) 20 J

b) 40 J

c) 50 J

d) 60 J

Answer 2

Answer:

d) 60 J

Explanation:

Mass of the body= 0.5kg

position , x(m)= 3t²+4t+5

velocity= 6t+4 m/s and acceleration=6 m/s^-2

Now the force exerted= 0.5 x 6 N = 3N

and Displacement in first 2 second= (position at t=2) - (position at t=0)

                                                          = (12+8+5) - (0+0+5)

                                                          = 25 - 5 = 20 m

Now the work done = Force exerted x Displacement in first 2 second

                                  = 3 N x 20 m =60 J

                                                                                    Hope you all understand