Question

The resistance to the motion of a bus is partly constant and partly varies as the square of the speed of 30km/he the resistance is 70π while at speed of 40km the resistance is 140π what is the speed of given the resistance of 230 what is the resistance at speed of 70km/hr

Answer 1

r = ms^2 + b
And you know that
30^2 * m + b = 70π
40^2 * m + b = 140π
subtract, and you have
700m = 70π
m = π/10
now find b, and then you want
ms^2 + b = 230
70^2*m + b =____

Answer 2

Thanks for your help