# Speed, Distance and Time GCSE Physics Question. Help please…

It takes me 20 minutes to walk from home to the bus station. I catch the bus from the bus station to work each morning. My bus journey is 10 miles and usually takes 30 minutes. I can catch a bus at 20 minutes past the hour or 10 minutes to the hour. When I get off the bus, it takes me 5 minutes to walk to work.

a) What is the average speed of the bus?

b) I have to be at work for 8:30. What time for the latest I can leave home to be at work on time?

My working out:

10 miles = 0.5h

Speed: 10 / 0.5 = 20mph

How would I use that to work out b?

Thank you and help is appreciated

• 1) I highly recommend that you use MathJax to edit you equations. 2) Assuming you must get to work at 8:30a.m., then in the ideal world where the bus runs every minute, if you were to walk from home, to the Bus station, then immediately get a bus to work, get off the bus and then walk to work, this would take $20+ 30 + 5 = 55$ minutes. So assuming no delays, the latest you can leave home is 7:35a.m. However, for your problem statement, and taking the bus schedule into account, the earliest time to depart home is 7:30a.m, and you arrive to work at 8:25a.m. – Winter Soldier Sep 14 '18 at 17:54

From bus stop to work you need $30+5=35$ minutes. If we subtract $35$ minutes from $8:30$ we get $7:55$. There is $7:50$ bus which you can catch if you leave house at $7:30$.