A motorist travelling at 72km/h has his eyes shut for 0.4s during a hard sneeze, calculate the distance covered by him during this time interval

Step 1: Convert speed from km/h to m/s.

$1 \, km/h = \frac{1000 \, m}{3600 \, s} = \frac{5}{18} \, \text{m/s}$

$v = 72 \, km/h = 72 \times \frac{5}{18} \, \text{m/s}$

$72 \div 18 = 4, \quad 4 \times 5 = 20$

$v = 20 \, \text{m/s}$

Step 2: Distance formula with constant speed.

$d = v \times t$

Step 3: Substitute values (with units).

$d = 20 \, m/s \times 0.4 \, \text{s}$

$20 \times 0.4 = 8$

$d = 8 \, \text{m}$

8 m