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The Wang family drives 560 km from Toronto to Montreal in7 h.

a) At what speed do they drive?
b) How long does the Wang family take to drive from Montreal to Toronto at 56 km/h?

User Bchang
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2 Answers

2 votes

Answer:

a)80km/h or in metres 22m/s

b) 10h

Explanation:

a) firstly, to find the speed we use the formula

speed=distance/time

s=d/t

d=560km, t=7h, s=?

now that we've identified them, we slot them into the formula.

s=d/t

s=560km/7h

s= 80km/h

for the metres part, you just convert the km to m by multiplying with 1000.

And to convert time into seconds, just change it to 60s then multiply by itself to give you 3600s =1h

and multiply by the number of hours given.

b) it's just the same using the above formula given but with a slight twist. We change it around so that we make t the subject.

t x s=d/t x t (first, we multiply t on both sides)

this gives us d= t x s ( second, we don't want d as the subject but t)

so d/s = t x s/s ( we divide s on both sides, where s cancels out with itself leaving t as our subject)

thus t= d/s

now that we've changed our formula, we can now start solving the equation.

t=d/s

t= 560km/ 56km/h

t=10h

User Micheal Hill
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0 votes

Answer:
(a) They drive 80km/h.
(b) It would take 10 hours.

Explanation:
(a) If the family drives 560km and arrives in 7 hours, they would have to be driving 80km/h. (Distance/Time = 560/7 = 80km/h).

(b) If the family drives 56km/h, it would take them 10 hours to reach their destination. (Distance/Speed = 560/56 = 10 hours).

User Ifma
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7.6k points