Posted by **SAM** on Sunday, January 30, 2011 at 5:46pm.

You stand at the top of a cliff while your friend stands on the ground below you. You drop a ball from rest and see that it takes 0.90 for the ball to hit the ground below. Your friend then picks up the ball and throws it up to you, such that it just comes to rest in your hand.

What is the speed with which your friend threw the ball?

- physics -
**Damon**, Sunday, January 30, 2011 at 5:50pm
The same speed with which it hit the ground.

v = g t

v = 9.8 m/s^2 (.9 seconds) = 8.8 m/s

- physics -
**SAM**, Sunday, January 30, 2011 at 6:30pm
Learning Goal: To learn to read a graph of position versus time and to calculate average velocity.

In this problem you will determine the average velocity of a moving object from the graph of its position as a function of time . A traveling object might move at different speeds and in different directions during an interval of time, but if we ask at what constant velocity the object would have to travel to achieve the same displacement over the given time interval, that is what we call the object's average velocity. We will use the notation to indicate average velocity over the time interval from to . For instance, is the average velocity over the time interval from to .

Find the average velocity over the time interval from 1 to 3 seconds.

Express your answer in meters per second to the nearest integer.

## Answer this Question

## Related Questions

- Physics - Bob has just finished climbing a sheer cliff above a beach, and wants...
- College Physics - Bob has just finished climbing a sheer cliff above a beach, ...
- Physics based Calculus - Bob has just finished climbing a sheer cliff above a ...
- Math - Marsha hits a tennis ball upward from the top of a 90 foot high cliff ...
- Physics - A 3.79 kg ball is dropped from the roof of a building 163.8 m high. ...
- Physics Correction - You drop a ball from a window on an upper floor of a ...
- calculus - A golf ball is hit off the top of a cliff that is 75 feet tall at an ...
- physics - A ball is thrown horizontally at 10.0 m/s from the top of a hill 50.0 ...
- Physics - A ball is thrown horizontally at 10.0 m/s from the top of a hill50.0 m...
- Math - A golf ball is hit off the top of a cliff that is 75 feet tall at an ...

More Related Questions