An object is launched into the ail' with an initial velocity given bym/s. Ignore air resistance.(a) At the highest point the magnitude of the velocity is(b) At t = 0.5 s the magnitude of the velocity is

The correct option is:

(a) At the highest point the vertical component of velocity of the object is zero whereas the horizontal component of velocity remains the same as it was initially. Therefore the magnitude of net velocity of the object at the highest point is equal to the initial horizontal component of velocity which is given to be 4.9 m /s.
(b) The magnitude of horizontal component of velocity remains the same during the entire flight, therefore one has to evaluate only the vertical component of the velocity after t = 0.5 s.The vertical component of velocity at after any time t from its starting position is given as:
v_y = v_0y – gt
Here v_0y is the initial vertical component of velocity, g is the free fall acceleration and v_y is the final vertical component of velocity.