# The coordinates of a body moving in a plane at any instant of time t are x = α t^2 and y= β t^2 .

Q: The coordinates of a body moving in a plane at any instant of time t are x = α t2 and y = β t2 . the speed of the body is.

Sol: x = α t2

$\large v_x = \frac{dx}{dt} = 2 \alpha t$

y = β t2

$\large v_y = \frac{dy}{dt} = 2 \beta t$

Speed $\large v = \sqrt{v_x^2 + v_y^2 }$

$\large v = \sqrt{(2 \alpha t)^2 + (2 \beta t)^2 }$

$\large = 2 t \sqrt{\alpha^2 + \beta^2}$