Question

1 point 14(ii) A car initially moves with a constant velocity and then with constant acceleration. Which graph shows this motion? ​

Answer 1

Answer:

Correct option is d

option

For 0<t<4 s :

Let the acceleration of the particle be a ( constant)

Initial velocity of the particle u=0

Using S=ut+

2

1

at

2

∴ x=0+

2

1

at

2

⟹x=

2

at

2

for 0<t<4

Thus the x-t graph is parabola symmetric about x axis for 0<t<4

Velocity of particle at t=4 s, v=0+a(4)=4a m/s

For t>4 s :

Acceleration of the particle is zero i.e a=0

∴ x=vt=4at for t>4 s

Thus x-t graph is a straight line for t>4 s