A particle is moving along x-direction with a constant acceleration a. The particle starts from `x=x_0` position with initial velocity u. We can define the position of the particle with time by the relation
`x=x_0+ut+(1)/(2)at^2`
plot the position of the particle in relation with time is following situations
(i) If initial position of the particle is on negativ x-axis, initial velocity is positive and acceleration is negative.
(ii) If initial position is positive, initial velocity is negative and acceleration is positive.

Options

A. 12
B. 9
C. 10
D. `1.8`

Answer

B

Explanation

`upsilon^(2)=u^(2)+2as`
`a=(upsilon^(2)-u^(2))/(2s)=((20)^(2)-(10)^(2))/(2xx135)=(300)/(270)=(10)/(9)ms^(-2)`
From first equation of motion
`upsilon=u+at rArr t(upsilon-u)/(a)=(20-10)/(10//9)=(10)/(10//9)=09s`