Question

A particle is moving along a straight line parallel to the x axis at a distance 'd' away from it. It moves with a constant velocity 'u'. At a point (x,d)what is the velocity along r̂ ?
1.uy /(x^2+y^2)^0.5
2.u
3.ux/y
4.ux/(x^2+y^2)^0.5

Answer 1

A particle is moving along a straight line parallel to the x axis at a distance 'd' away from it. It moves with a constant velocity 'u'. At a point (x,d) what is the velocity along $\hat{r}$ ?

1.uy /{x^2+y^2}^0.5

2.u

3.ux/y

4. $u x / \{x^2 + y^2\} ^0.5$

Answer:

From triangle ABC $u(r) = u\frac{x}{\sqrt{x^2 + y^2}}$

Answer: "4"