You drive your car from home at an average velocity of 82 km/h for 3h. Halfway to your destination, you develop some engine problems, and for 5h you nurse the car the rest of the way. What is your average velocity for the entire trip?
2006-10-14 18:58:29 · 6 answers · asked by yoo whoo 1 in Science & Mathematics ➔ Physics
distance = velocity * time
82 km/h * 3 h = 246 km, the halfway point
meaning you took 5h for the other half, also 246 km. So the total distance is 246*2=492km
velocity = distance / time
(246km * 2) / (3h + 5h)
= 492 km / 8 h
= 61.5 km / h
round to 62 km/h
2006-10-14 19:04:17 · answer #1 · answered by Glenn 2 · 0⤊ 0⤋
Let the average velocity of car for 3 h be v i.e. 82km/h
distance = speed*time = 82 * 3 = 246 km
for 5 hours, the car is in the position of rest so the distance covered by it is 0 km,
average speed = total distance/total time
=> average speed = 246 + 0/3 +5
246/8 = 30.75 km/h
that's it!
2006-10-15 04:35:19 · answer #2 · answered by § mǎddy § 2 · 0⤊ 0⤋
Lets the distance is x metres.
velocity = distance travelled by the car /time taken
so
x/2 =82km/h * 3h = 246 km
similarly avg velocity = 246km/5h= 49.2 km/h
so the avg velocity of the car is (82+49.2)km/h= 132 km/h
i.e avg velocity of the car to reach destination from home is 132km/h
avg velocity for the entire trip i.e travelling from destination to home is 132+132= 264 km/h
so the avg velocity of entire trip is 264 km/h or73.3m/sec
2006-10-15 02:37:41 · answer #3 · answered by kanna 1 · 0⤊ 0⤋
Why is everyone making this so complicated? You went 246 km in 3 hours. Then you went 246km in 5 hours. That's 492km in 8hours., or about 61.5kph.
Math is a whole lot easier if you just learn to word the problem in the simplest terms instead of trying to make it fit the equations.
A little common sense would have told kanna that 246kph was a ridiculous answer.
2006-10-15 10:03:43 · answer #4 · answered by Nomadd 7 · 0⤊ 0⤋
8 hours per 600 km = 1.333333333333333333333333..............ave velocity to destination but would double distance for return if necessary
2006-10-15 02:14:10 · answer #5 · answered by Anonymous · 0⤊ 0⤋
hate physics....like biology more. I hate phycis and gen chem 2. Gen Chem 2 is so dumb. I have to retake it and be in college forever.
2006-10-15 02:07:33 · answer #6 · answered by rumman 2 · 0⤊ 0⤋