Question

A ball starts from origin at time t=0 secs with an initial velocity in x-component 30m/s and a y-component is -25m/s. So, the ball moves in xy-plane with acceleration 4.2. Find the total velocity at time t=3.2 seconds

Answer 1

$$v_0=\sqrt{30^2+(-25)^2}=39.05\frac{m}{s}$$

The magnitude:

$$v=v_0+at=39.05+4.2(3.2)=52.5\frac{m}{s}$$

The direction is

$$\theta=\arctan{\frac{25}{30}}=39.8\degree\ below\ x-axis$$