Motion/distance problem. I cant understand :(?

Question

Two motorcycles travel toward each other from Chicago and Indianapolis which are about 350 km apart, at rates of 110 and 90 km/h. They started at the same time. In how many hours will they meet?

Answer 1

Driver 1, going 110 kph...
Driver 2, going 90 kmh

In order for them to meet, they have to have travelled the same amount of time (T).

Rate * Time = Distance

Driver 1: 110 T = distance travelled
Driver 2: 90 T = distance travelled

These two distances together must equal 350 km.

110 T + 90 T = 350
200 T = 350
T = 1.75 hours (or 1 hour, 45 minutes)

Answer 2

Hi RSS. The two motorcycles are approaching each other at a combined speed of 200 km/h (110 + 90). So, at this combined speed, how long will it take them to travel 350 km?

350/200 = 1.75 hours.

Best wishes and good luck.

Answer 3

"Newtonian mechanics?"

Not sure about that, but simple math yields the same correct answer.

If you're ever in doubt, write down what you know, in this case it's the 350 km distance and the combined speed of 200 km/h. Then look at what you're trying to find: hours. Which means that you need the inverse of 200 km/h (so the hours are in the numerator, not the denominator). What else are you going to do with the inverse of 200 but multiply it by 350.

Thus 350/200=1.75, or one hour, 45 minutes.

Answer 4

basic formula:

distance = speed * time

distance = 350 km

speed = 110 +90 = 200 km/h

time = distance/speed
= 350/200 = 1.75 hr = 1 hr 45 min

Answer 5

Using Newtonian mechanics, the total closure rate is 200 kph. So the time will be 350/200 hours, or about an hour and 45 minutes.

Answer 6

You have to find the time in which they travel and have gone through a distance of 350km.

If you don't understand what I'm saying you can always e-mail me =D.

t(110km+90km)=350km

t=time

t(200km)=350km

Divide by 200km on both sides.

7/4hours=t

Answer 7

One hour and 45 minutes.