Answer:
1. y=mx+b
(5 , 5) (10 , 10)
5m+b=5 10m+b=10
10m+b-5m-b=5
5m=5
m=1
5+b=5
b=0
So for 1---10s the slope is: y = x
2. y=mx+b
(10 , 10) (35 , 10)
10m+b=10 35m+b=10
35m+b-10m-b=0
25m=0
m=0
b=10
So for 10-----35s the slope is: y=10
3. y=mx+b
(35 , 10) (0 , 0)
35m+b=10 b=0
35m=10
m=2/7
So for 35----40s the slope is: y= 2/7 x
