NEET Physics Mathematical Tools Questions Solved


A particle travels with speed 50 m/s from the point (3, 7) in a direction 7i^-24j^. Find its position vector after 3 seconds.

(A)  151i^+45j^

(B)  45i^-137j^

(C)  151i^+45j^

(D)  4.5i^-151j^

Concept Videos :-

#20 | Vectors: Introduction
#21 | Vectors: Addition
#22 | Vectors : Subtraction

Concept Questions :-

Resultant of Vectors

(B)

 

 

                           

Direction of velocity is along 7i^-24j^Unit vector v^= VectorMagnitude                      = 7i^-24j^72+-242                    v^= 7i^-24j^25Velocity v= Magnitude of velocity × Direction                  = Speed × v^                  = 50 × 7i^-24j^25                  = 14i^-48j^Displacement x= Velocity × Timex= 14i^-48j^ × 3       = 42i^-144j^

Also, displacement x= Final position - Initial position            42i^-144j^           = xi^+yj^-3i^+7j^Comparing in x and y direction- 42= x-3  x= 45-144= y-7  y= -137So, final position vector, xi^+yj^  = 45i^-137j^

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