Question

Estimate how long it would take one person to mow a football field using an ordinary home lawn mower. Assume the mower moves with a 1 km/h speed, and has a 0.6 m width

Answer 1

Answer:

t = 11.9 h = 0.49 day

Explanation:

First of all, we will find the area covered by the mower per unit time:

$Rate\ of\ Area\ Covered\ by\ Mower = vw$

where,

v = speed of mower = 1 km/h = 1000 m/h

w = width of mower = 0.6 m

Therefore,

$Rate\ of\ Area\ Covered\ by\ Mower = (1000\ m/h)(0.6\ m)\\Rate\ of\ Area\ Covered\ by\ Mower = 600\ m^{2}/h$

Now, the standard football ground has an area of:

A = 105 m x 68 m = 7140 m²

Therefore, The time required to mow the lawn will be:

$Time\ to\ Mow\ the\ Lawn = t = \frac{A}{Rate\ of\ Area\ Covered\ by\ Mower}\\t = \frac{7140\ m^{2}}{600\ m^{2}/h}$

t = 11.9 h = 0.49 day