A person in car, travelling at 90 kilometers per hour, takes 2 seconds to go past the building on the side of the road. Calculate the length of the building in meters help

Ph Ch 5 Check Yourself When you are driving at 90 km/h, how much more distance do you need to stop than if you were driving at 30 km/h? For the same force, why does a longer cannon impart more speed to a cannonball? ~Nine times farther.

Step-by-step explanation:

very simple thought experiment :

he is going 90 km/h (90 kilometers per hour), so, he moving 90 km in 1 hour.

how far is he going in just 2 seconds ?

so, we get two ratios.

90km/1 hour = 90,000 meter / 1 hour

x meter / 2 seconds

we need to bring both ratios (they are fractions) to the same dimension of the denominators, so that we can then bring them to the same denominator.

the first is dealing with an hour.

the second one with (2) seconds.

so, how many seconds are in 1 hour ?

60 seconds per minute, 60 minutes in the hour.

60×60 = 3600 seconds.

so, now we know, the first ratio is also

90,000 meter / 3600 seconds

now we need the factor to to multiply numerator and denominator with to bring 3600 down to 2.

3600 × f = 2

f = 2/3600 = 1/1800

now we get

90,000 / 3600 × (1/1800) / (1/1800) =

(90000 / 1800) / (3600 / 1800) = 50 / 2

so, 90km/h is the same speed as 50 meter / 2 seconds.

and therefore we know, the building was 50 meters long.

the second one

Step-by-step explanation: