Question

An object moves according to relation r= 2t^2 î+3tj. Its speed at t= 1 sec is
(1) 7 m/s
(2) 5 m/s
(3) 5/2m/s
(4) 10 m/s​

Answer 1

Answer:Taking 2t² i + 3t j and substituting t with 1, we get -

2i + 3j

Now using differentiation-

d/dx( 2i + 3j)

= (3) 5/2 m/s

Explanation: