Physics

Problem

A ball slides on a frictionless horizontal table so that its velocity components at any instant are

v_x = 4t

and

v_y = 3t^{2}

, where

v_x

and

v_y

are in

\text{m\,s}^{-1}

and

t

is in seconds. a. (a) Write the expression for the magnitude of the velocity (speed) at time

t

. b. (b) Calculate the speed of the ball at

t=2.0\,\text{s}

. c. (c) Express the value obtained in part (b) in

\text{km\,h}^{-1}

. (Take

1\,\text{m\,s}^{-1}=3.6\,\text{km\,h}^{-1}