Physics homework help please
I'm taking grade 11 physics and we just started, I'm so lost most of the time, if people could just help me with some questions and give a basic explanation to the answer that would be so cool! Thanks!
During a short interval of time the velocity, v, in m/s of an automobile is given by v = at^2 +bt^3. Determine the units of "a" and "b"
I completely don't get this question.
And
An impatient motorist considers speeding as he travels between two cities. If the trip normally takes
2.80h at an average speed of 100km/h, how much time will be saved if he exceeds the speed limit by
10.0km/h
Is this total distance of this travel 280km? And If I'm right do I just 280/110?
Halp please
September 21, 2011
3 Comments • Newest first
[quote=indu95]By saying that wouldn't it be m/s^2 not 3? Meaning b is m/s^3.
so if you replace "t" with "s" is A m/s or m?[/quote]
Unit conversions can be treated like algebra. Time = seconds represented by s. Distance = metres
(s^2)A =m/s
A= m/(s^3)
[quote=HolyDragon]V = m/s
The current units of at^2 +bt^3 are a(s)^2 and b(s)^3. You want to aim for m/s. So A must be m/s^3. Figure out B yourself.
For the second part. You have the distance, find the difference in time now.[/quote]
By saying that wouldn't it be m/s^2 not 3? Meaning b is m/s^3.
so if you replace "t" with "s" is A m/s or m?
V = m/s
The current units of at^2 +bt^3 are a(s)^2 and b(s)^3. You want to aim for m/s. So A must be m/s^3. Figure out B yourself.
For the second part. You have the distance, find the difference in time now.