Problem 14P

(II) Calculate the average speed and average velocity of a complete round trip in which the outgoing 250 km is covered at 95 km/h. followed by a 1.0-h lunch break, and the return 250 km is covered at 55 km/h.

Solution 12Q

A baseball is thrown upward with a velocity of 120km/h. We will find its speed when it comes back to level as it is hit.

It makes the solution of free fall problems easier, if we choose the initial point as origin and the initial velocity direction to be positive.

Step 1 of 2

(initial velocity of baseball)

(gravitational acceleration is negative because we chose the downward to be negative)

(the object is passing back to the point it is thrown. Where the velocity is asked. The initial and final points are the same points. So displacement is zero)

(final velocity of baseball)