If you are driving 72 kmh along a straight road and you look

If you are driving 72 km/h along a straight road and you look to the side for 4.0 s, how far do you travel during this inattentive period? 18 m 20 m 40 m 80 m

Solution

driving at 72km/h

converting speed to metre / sec

1 km = 1000 m

1 hour = 60* 60 seconds = 3600 seconds

1 km/hour = 1000/ 3600 metre / second

72 km/ hour = 72* ( 1000/ 3600) = 20 m / sec

therefore, in 1 second distance covered = 20 m

so, in 4 seconds distance travelled = 20* 4= 80m

(option d)