- #1

mamadou

- 24

- 1

## Homework Statement

A bascketball player , who has a weight of

*jumps vertically with a height of*

**890 N**,

**1.2 m ,**1- Find his speed when he left the floor.

2- If the time that takes the basketball player to quit the floor is

*, what is his average acceleration ?*

**0.3 s**(I don't understand this question at all, is there any function of time that I've to found or anything like this ?)

3-Find out the value of the force that the player applies to the ground .

## Homework Equations

F = m.a ..(1) , Vf²-Vi² = 2 .a.d ..(2) , p =m.g ..(3)

## The Attempt at a Solution

1- For the 1'st question it's quite easy just by using the formula (2) above , we get

[tex] V_{i} = \sqrt{2.g.d } = 4.84 m/s [/tex]

2- for the second I think that it's :

[tex] a = \frac{\Delta V}{ \Delta t} = \frac{V_{i}}{0.3} = 16.16 m.s^{-2} [/tex]

3- For this I didn't understand at all , by using the Newton 2'nd law I get :

**f = m.a**( where f is the magnitude of the applied force on the ground ) , but when the player applies that force he is at rest in the ground , not moving , which means a = 0 , thus f = 0 , isn'it ?