Question

The position vector of a particle is determined by the
expression r = 3t^2î + 4t^2 j+ 7k. The displacement tra-
versed in first 10 seconds is:
(a) 100 m
(b) 150 m
(c) 300 m
(d) 500 m​

Answer 1

Answer:

r (i)= Initial position vector

r (f) = Final position vector

Since r is the finction of time.

r(i)=r(0)=7 k^   

r(f)=r(10)=3*10² i^ + 4*(10)² j^ +7 k^

Now ,

Displacement vector= r(f)-r(i)

D= |300 i^ + 400j^ +(7-7)k^ |

 

=500