Question
Question: The acceleration of the particle is...
The acceleration of the particle is

A
0
B
4 m/s²
C
-4 m/s²
D
None of these
Answer
-4 m/s²
Explanation
Solution
The position of the particle is given by x(t)=2(t−t2)=2t−2t2.
The velocity of the particle is the first derivative of position with respect to time: v(t)=dtdx=dtd(2t−2t2)=2−4t.
The acceleration of the particle is the first derivative of velocity with respect to time (or the second derivative of position): a(t)=dtdv=dtd(2−4t)=−4.
The acceleration is constant and equal to −4 m/s².