Question

you are traveling in a convertible with the top down. the car is moving at a constant velocty of 25 m/s due east along falt ground. you throw a tennis ball straight upward at a speed of 15 m/swhen the ball just leaves your hand, what is the speed of the ball as measured by an observer on the side of the road

Answer 1

Answer:

Teh velocity of ball with respect to the ground is 29.2 m/s.

Explanation:

Velocity of car, vc = 25 due m/s east

velocity of ball with respect to car, v(b,c) = 15 m/s due Z axis

Write the velocities in the vector form

$\overrightarrow{v}_{c}=25 \widehat{i}\\\\\overrightarrow{v}_{(b,c)}=15 \widehat{k}$

The velocity of ball with respect to ground is

$\overrightarrow{v}_{(b,c)}= \overrightarrow{v}_{(b,g)}-\overrightarrow{v}_{(c,g)}\\\\15 \widehat{k} = \overrightarrow{v}_{(b,g)} - 25 \widehat{i}\\\\\overrightarrow{v}_{(b,g)} = 25 \widehat{i} + 15 \widehat{k}\\\\v_{(b,g)}=\sqrt{25^2 + 15^2}=29.2 m/s$