The position vector of a particle is \(\vec{r}\) = 4t2\(\hat{i}\) + 2t\(\hat{j}\) + 3t\(\hat{k}\). The speed of the particle at t = 5 s is –
A. 42 ms-1
B. 3s
C. 3 ms-1
D. 40 ms-1
Answer:A
The position vector of a particle is \(\vec{r}\) = 4t2\(\hat{i}\) + 2t\(\hat{j}\) + 3t\(\hat{k}\). The speed of the particle at t = 5 s is –
A. 42 ms-1 B. 3s C. 3 ms-1 D. 40 ms-1