One day your drive to work takes 10 minutes and you average 30 mph. The next day the drive takes 15 minutes. What is your average speed that day?
2007-05-20 12:46:28 · 10 answers · asked by KG 3 in Science & Mathematics ➔ Mathematics
okay, so distance = speed * time
distance = 10/60 * 30 = 300/60 = 5 miles
speed = distance/time
= 5 divided by 15/60
= (5*60)/15 = 300/15 = 20 mph
2007-05-20 12:50:27 · answer #1 · answered by Kerynella 2 · 0⤊ 0⤋
If you average 30 MPH and take 10 minutes, your work is 1/6 of 30 miles away or 5 miles away. If it takes you 15 minutes to drive 5 miles,then your average speed in 20 MPH.
2007-05-20 12:50:56 · answer #2 · answered by Bradley B 2 · 0⤊ 0⤋
10 minutes is 1/6 of an hour
15 minutes is 1/4 of an hour
(1/6 hours) * (30 mph) = 5 miles
so the total distance is 5 miles
now using the same basic equation above:
(average speed) = (5 miles) / (1/4 hours) = 20 mph
So, the average speed you must travel to go 5 miles in 15 minutes is 20mph
2007-05-20 12:56:33 · answer #3 · answered by Hatty 2 · 0⤊ 0⤋
think about it this way....
so if it takes you 10 minutes at 30 mi/hr how far are you going?
or in an hour you could go 30 miles
but you are driving 1/6 of that distance (10 mins/1 hr)
so you are going 30/6 miles
or 5 miles
so then if your speed the next day is 5 mi/15 mins
you convert that to hours or multiply both top and bottom by 4
so you get 20 mi/60 mins ( the opposite of fraction reducing)
or 20mi/hr
2007-05-20 12:52:33 · answer #4 · answered by brebitz 2 · 0⤊ 0⤋
The distance you travel each day is 30mph * (10/60)hr
= 5 miles.
The next day you drive 5 miles in 15 minutes, which is 4 * 5 = 20 miles in an hour, meaning your average speed is 20mph.
2007-05-20 12:52:12 · answer #5 · answered by Anonymous · 0⤊ 0⤋
distance=10/60*30=5 miles
average speed the next day=5/15/60=20mph. answer
2007-05-20 12:51:48 · answer #6 · answered by Anonymous · 0⤊ 0⤋
let v represent velocity in mph
let d represent distance in miles
let t represent time in seconds
v=d/t
d=vt
=30*600
=18 000 miles
v=d/t
=18 000 / 900
= 20 mph
2007-05-20 12:53:06 · answer #7 · answered by de4th 4 · 0⤊ 0⤋
10min/60min = 0.167 hours
30 miles/hour x 0.167 hours = 5 miles
So since yesterday, it took 10 minutes @ 30mph to drive 5 miles, it should take:
15min/60min= 0.25 hours
5miles/0.25 hours = 20mph
2007-05-20 12:52:22 · answer #8 · answered by K.T. Y 1 · 0⤊ 0⤋
you guys cant do distance=s * t cuz you're trying to figure out the speed...you cant put it in the equation
2007-05-20 12:54:41 · answer #9 · answered by Anonymous · 0⤊ 0⤋
20 mph
Doug
2007-05-20 12:49:53 · answer #10 · answered by doug_donaghue 7 · 0⤊ 0⤋