Question

9. Displacement of a particle
moving on straight line is given
by š= 2t'+4. Find work done
after 38

Answer 1

Answer:

Given:

The displacement of particle is given by x=6+12t−2t

2

To find:

Distance covered by particle in first 3 sec.

Since the expression is for displacement. So it is necessary to find that the particle does not change its direction.

Time at which the velocity of the particle becomes zero →

v=

dt

dx

​

=

dt

d

​

(6+12t−2t

2

)

=12−4t

for velocity will be zero →0=12−4t

t=3 sec

So, its direction will chagne after 3 sec.

So, distance in 3 sec →

x

3

​

=6+12t−2t

2

Put t=3 s

x

3

​

=6+12(3)−2(3)

2

=42−18 m

=24 m

position of particle at t=0

x

0

​

=6+12(0)−2(0)

2

=6 m

So, distance covered in 3 sec

x=x

3

​

−x

0

​

=24−6 m

=18 xplanation: