education

# When a stone is thrown vertically upwards, it’s distance (d metres) after t seconds is given by the formula d=60t-10t². For values of t from 1 to 5 seconds using 2cm to 1unit on the t axis and 2cm to 20units on the d-axis. Calculate your graph

1989 Nov. G.C.E Homework
When a stone is thrown vertically upwards, it’s distance (d metres) after t seconds is given by the formula d=60t-10t². For values of t from 1 to 5 seconds using 2cm to 1unit on the t axis and 2cm to 20units on the d-axis. Calculate your graph

### (I) how long does it take to reach a height of 70 metres? (II) determine the height of the stone after 5 seconds (III) after how many seconds does it reach to it maximum height (IV) determine the slope of the graph when t = 5 secondsSolution

First we’ve to find distance d(meters)
Formula d = 60t-10t²,
For values of t from 1 to 5 seconds
When t = 1
distance d (meters) = 60t-10t²
60(1)-10(1)² = 60-10
50( distance is 50 when time is 1 second)

When t = 2
distance d (meters) = 60t-10t²
60(2)-10(2)² = 120-10(4)
120-10×4 = 120-40
80( distance is 80 when time is 2 second)

When t = 3
distance d (meters) = 60t-10t²
60(3)-10(3)² = 180-10×9
180-90 = 90 ( distance is 90 when time is 3 second)

When t = 4
distance d (meters) = 60t-10t²
60(4)-10(4)² = 240-10×16
240-160 = 80( distance is 80 when time is 4 second)

When t=5
distance d (meters) = 60t-10t²
60(5)-10(5)² = 300-10×25
300-250 = 50 ( distance is 50 when time is 5 second)

Plot a graph of distance against time ( where distance(d metres) will be y axis and time ( t seconds) will represent x axis
Let y represent 20cm at 2units
And let X represent 1cm at 2units

How to plot graph of d(metres) against t (secs)
Watch this video

### Oluwamuyide Peter

My name is seyi, the main aim of creating this platform is to help users get information like school updates, electrical engineering topics, school project and many more for free