Question Details

A body starts from the origin and moves along the x-axis such that velocity at any instant is given by (4t³-2t) , where t is in second and velocity is in m/s. What is the acceleration of the particle, when it is 2m from the origin?

Options

A

28 m/s²

B

22 m/s²

C

12 m/s²

D

10 m/s²

Correct Answer :

22 m/s²

Solution :

The correct option is 22 m/s².

To find the acceleration of the particle when it is at a distance of 2 m from the origin, we can follow these steps:

Step 1: Find the position function, x(t)
The velocity v(t) of the particle at any instant t is given by:
v(t)=4t3-2t
Since velocity is the rate of change of position, we can integrate the velocity function with respect to time to get the position x(t):
x(t)=v(t)dt=(4t3-2t)dt
x(t)=t4-t2+C
where C is the constant of integration.

Since the particle starts from the origin, at t=0, the position x(0)=0:
0=04-02+CC=0
Therefore, the position equation is:
x(t)=t4-t2

Step 2: Find the time when the particle is 2 m from the origin
We set the position x(t)=2:
t4-t2=2
Letting y=t2, the equation becomes a quadratic equation:
y2-y-2=0
Factoring the equation:
(y-2)(y+1)=0
This gives y=2 or y=-1.
Since y=t2 must be non-negative, we reject y=-1. Thus:
t2=2

Step 3: Calculate the acceleration
Acceleration a(t) is the derivative of velocity v(t) with respect to time:
a(t)=dvdt=ddt(4t3-2t)=12t2-2
Substitute t2=2 into the acceleration equation:
a=12(2)-2=24-2=22 m/s2

The acceleration of the particle when it is 2 m from the origin is 22 m/s².

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