Mark the correct alternative in the following:
The distance moved by a particle travelling in a straight line in t seconds is given by s = 45t + 11t2 – t3. The time taken by the particle to come to rest is
If we are given the distance travelled(s) as a function of time, we can calculate velocity(v) by
s = 45t + 11t2 – t3
Differentiating with respect to time, we get
If the particle is at rest, then its velocity will be 0
v(t)=45+22t-3t2=0
Solving the quadratic equation, we get
or t=9 sec
Since time can’t be negative therefore t=9secs.