The position vector of a moving particle at time t is r=3i+4t²j-t³k .. Its displacement during the time interval t=1 s to t=3 s is a) j-k b) 3i+4j-k c) 9i+36j-27k d) 32j-26k

Correct answer is 32j-26k Explaination:: r=3i+4t²j-t³k r_(t=1s)=3i+4j-k r_(t=3s)=3i+36j-27k Displacement = (r_(t=3s))-(r_(t=1s)) = 32j-26k

Chapter: Physics· JEE

The position vector of a moving particle at time t is r=3i+4t^2j-t^3k .. Its displacement during the time interval t=1 s to t=3 s is

The position vector of a moving particle at time t is \(r=3i+4t^2j-t^3k\) .. Its displacement during the time interval t=1 s to t=3 s is

a) \(\hat{j}-\hat{k}\)

b) \(3\hat{i}+4\hat{j}-\hat{k}\)

c) \(9\hat{i}+36\hat{j}-27\hat{k}\)

d) \(32\hat{j}-26\hat{k}\)

Doubtly Asked 28 May 2021 Updated 23 Jun 2021 Student doubt vectors Save WhatsApp Report

Best answer

Correct answer is \(32\hat{j}-26\hat{k}\)

Explaination::
\(\vec{r}=3\hat{i}+4t^2\hat{j}-t^3\hat{k}\)

\(\vec{r}_{t=1s}=3\hat{i}+4\hat{j}-\hat{k}\)

\(\vec{r}_{t=3s}=3\hat{i}+36\hat{j}-27\hat{k}\)

Displacement = \((\vec{r}_{t=3s})-(\vec{r}_{t=1s})\)

=\(32\hat{j}-26\hat{k}\)

Doubtly · 23 Jun 2021 Report

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