Question

1. The fastest serve of tennis champion Roger Federer stands at 230 km/h. Assuming constant velocity and that his opponent is 22 meters away (about the length of a tennis court), derive the time that the ball will take to reach the opponent.

2. A rocket is launched from cape Canaveral with a constant acceleration of 20 m/s. After 2 minutes,

   – what is the speed of the rocket? – How far has the rocket traveled?

   Hint: Use the first and second equations of motion.

Answer 1

A) Lets assume the tennis champion Roger Federer serves the ball with his fastest speed 230km/h.

The opponent is standing 22 meter away. To calculate the time that ball will take to reach the opponent use the following formula.

V₀ = 230km/h = 63.88 m/sec
S = Distance to the opponent = 22 meters

It will take mere 0.344 seconds for ball to reach to opponent.

B) Given information,

Acceleration = 20 m/s²
T = 2 minutes = 120 Seconds
Initial velocity = V₀ = 0 m/s
Final Velocity = V_f = ? m/s
Initial distance = S₀ = 0 meters
Distance traveled by rocket = S = ? meters

To get the final velocity and distance traveled by rocket in 120 seconds can be calculated using following formulas

Distance traveled can be calculated as follows

Hence rocket would have traveled 144000 meters distance in 2 minutes

Hope this helps! All the best!