Question

Devante runs a 100-meter race. 5 seconds after the race started Devante is 35 meters from the starting line and reaches his max speed; he runs at this max speed for the rest of the race. Devante notices that he is 71 meters from the starting line 9 seconds after the race started. What is Devante's max speed? meters per second Preview Suppose Devante runs for an additional z z seconds after reaching his max speed... How far will Devante travel during those additional z z seconds? meters Preview What is Devante's distance from the starting line 5 + z 5+z seconds after the race started? meters Preview What is Devante's distance from the starting line x x seconds after the race started (provided x ≥ 5 x≥5)?

Answer 1

a) The max speed of Devante is 9 meter per second.

b) Devante travel
`(z\ z*9 \ meter/sec)` for additional
`zz \ seconds`.

c) Devante's distance from stating line 5+z seconds after the race started is
`35\ meters+z*9\ meter / sec`.

d) Devante's distance from starting line x x seconds after the race started is
`35\ meters+(x \ x-5)*9\ meter/sec`, Provided
`x\geq 5`.

Explanation:

a) Devante reaches 35 meter away from starting line in 5 seconds and after 9 secs he realizes he is 71 meter away from starting line.

So,

`Distance=71-35=36\ meters`

`Time=9-5=4\ seconds`

Then,

`Max \ speed \ of \ Devante =36/4=9\ meter/second`

b) Devante run additionally for z z seconds after reaching his max speed.

So,

`Distance\ covered\ additionally=z\ z*9\ meter/second`

c) Devante's distance from starting line 5+z seconds after..

`Distance\ covered\ initially\ in\ 5\ seconds=35\ meters`

So,

`Total\ distance=35\ meters+((5+z)-5)*9\ meter/sec`

`=35\ meters+(z)*9\ meter/sec`

d)
`Initial\ distance=35\ meters`

`Remaing\ seconds\ after\ reaching\ 35\ meters=x\ x-5\ sec`

So, provided
`x\geq 5`.

`Devante's\ distance\ from\ starting\ line =35\ meters+(x\ x-5\ sec)*9\ meter/sec`