Question

A driver can stop his car from the red signal at a distance of of 20 m when he drives at 36 kmph

Answer 1

Answer:  2.0 seconds & 2.75 seconds

Step-by-step explanation:

$d=\dfrac{s\times r}{3.6}\quad where;\\\\\bullet d=\text{reaction distance (in meters)}\\\bullet s=\text{speed (in km/hr)}\\\bullet r=\text{reaction time (in seconds)}\\\bullet 3.6=\text{needed to convert km/hr into meters/second}\\\\\\\large{\text{When d=20m and s=36}}\\\\20=\dfrac{36}{3.6}\times r\\\\20=10r\\\\\large{\boxed{2=r}}\\\\\\\text{When d=41.25m and s=54}\\\\41.25=\dfrac{54}{3.6}\times r\\\\41.25=15r\\\\\large\boxed{2.75=r}$