Question

The question below has two statements, I and Impark your answer as
A moving train moves Y meters in t seconds. Find its acceleration.
I. Y=t³-4t³ + 16t - 2
II. Velocity at that moment was 20 m/sec.

• A. Question can be answered by using any one statement alone, but not by using other statement alone.
• B. Question can be answered by using either of the statements alone.
• C. Question can be answered by using both the statements together, but it cannot be answered by using either of the statements alone.
• D. Question cannot be answered even by using both the statements together.

Answer 1

The Correct Option is C

We have been given an expression of displacement in terms of time. Thus, differentiating this equation with respect to time once will give us an expression for velocity, and differentiating once again with respect to time will give us an expression for acceleration.
Hence,
\(V = 3t^2 - 8t + 16\) – (A)  
\(A = 6t - 8\)  – (B)
While we have obtained the expressions for velocity and acceleration, we cannot determine their absolute values at a particular time simply from the given statement 1.
Now, we go to Statement II
we have:
\(20 = 3t ^ 2 - 8t + 16\) after solving the equation we get,
 \(t=4+2( \sqrt 7)\)
When we put the value of t in (B), we get value of acceleration.
 
The correct option is (C)