Anonymous

# English+ Math question~~

An enthusiastic batsman hit the cricket ball straight up with a velocity of 20 metres per second. The equation for the flight of the ball is

h= 1+20t-[5t(平方)]

where h represents the height in metres after t seconds.

a. complete the square to enable you to find the greatest height reached by the ball.

b. Draw a sketch of the motion of the ball by graphing h vensus t in the space below.

Can anyone do it for me cus can't really understand what I should do~ Thank you la

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• 小貝
Lv 4

I doubt it's a physic question....

h = －５（ｔ平方　－４ｔ　＋　４）　＋２０　＋１

h= －５（ｔ－２）平方　＋２１

The first term is negative or zero, therefore when t equals 2, the first term will be zero,

that is, you don't have to decrease the sum, and this is the maximum.

The tallest height it can reach is 21 meters at the moment of 2nd second.

I can't use this to draw a sketch, so I can't complete this part.

I can give you some advice...

This sketch is a "parabola", and the "vertex" is at ( 2, 21 )

plus~ t is the horizontal axis , h is the vertical axis.