NEET2023PhysicsMotion in One DimensionActual
The position of a particle is given by r (t)=4 t i +2 t^2 j +5 k where t is in seconds and r in metre. Find the magnitude and direction of velocity v(t) , at t=1 ~s , with respect to x -axis.
Options
- A3 2 ~ms ⁻¹, 30^
- B3 2 ~ms ⁻¹, 45^
- C4 2 ~ms ⁻¹, 45^
- D4 2 ~ms ⁻¹, 60^
Correct answer
C. 4 2 ~ms ⁻¹, 45^
Step-by-step solution
aligned & r (t)= (4 t i +2 t^2 j +5 k ) m & d r (t) d t =4 i + .4 t j |_ t=1 ~ms ⁻¹ & v =4 i +4 j ~ms ⁻¹ & | v |= 4^2+4^2 =4 2 ~ms ⁻¹ & = v_y v_x = 4 4 =1 & =45^ aligned