Travel: On a road trip daddy is letting Tiffany steer the car. While Tiffany bounces softly on daddy’s lap, daddy is casually accelerating six miles per hour per minute. How far to they travel from the point they’re going 30 mph to when they’re going 90 mph?

Snack Time: Leslie is eating an enormous double-scooped ice-cream cone while Brenda is sucking on a huge Popsicle. Leslie's long licks up the side and along the top of her two scoops each average 8 seconds and 5 such licks consume an ounce of ice cream. Meanwhile, Brenda's sucking strokes are only 4 seconds long. But the juice-bar is so big she can only contain 2 inches of frozen fruity goodness in her mouth at a time. It takes 20 such strokes for Brenda to wear away an inch of her tasty treat. If Leslie’s ice cream cone is 16 ounces and Brenda’s Popsicle is 9 inches long, and it takes Leslie just as long to eat the cone as it does Brenda the last two inches of Popsicle, then which girl will finish their snack first, and by how much time?

Sleep Time: On Friday night, Teresa has a slumber party with six other girls. Daddy takes 30 minutes to tuck Teresa in, plus 5 minutes each to tuck in the other girls at the party, except Veronica with whom he takes 45 minutes. Daddy also takes 20 minutes to tuck in Teresa's little sister, Holly, and an hour to tuck in Teresa's older sister, Barbie. At what time does Daddy have to start getting girls ready for bed in order to have them all in bed by 10:00 pm?

[–] ftbd 11 points 2 months ago (1 children)

I was not ready for the truly unholy unit of mile per hour per minute

[–] JustAnotherKay@lemmy.world 4 points 2 months ago (1 children)

I mean that's just how acceleration works. Speed is distance over time, acceleration is change in speed over time, hence distance over time (speed) over time

[–] ftbd 4 points 2 months ago (2 children)

That's not the problem. Coming from metric, I expected m s^-2^ for acceleration. The imperial units for distances are weird enough in their own right – but using two different units of time for the two time derivatives is truly unholy.

[–] uriel238@lemmy.blahaj.zone 2 points 2 months ago* (last edited 2 months ago)

I use mph because that's what the speedometer reads. But mile/min² is easy to compute by dividing mile/hr/min by 60. Once the starting and ending speed are converted (assuming impulse is a constant) the law of accelleration neatly applies.

[–] JustAnotherKay@lemmy.world 0 points 2 months ago (1 children)

See I glossed over that because that's an entirely nonsensical issue. Do you measure the speed of your vehicle based off how much distance you cover per second or per hour? And then there's the fact that it's a math problem, written at roughly a middle school level - half the problem is figuring out how long it takes them to get up to the desired speed and if they did that in a person hour scale it would leave almost no math for the student to do

[–] ftbd 1 points 1 month ago

Especially in a middle school math/physics setting, I would expect reasonable units. Otherwise, how would kids understand the relationship between force and acceleration? Do you use mile / hour / min for the acceleration due to gravity as well? Do you have a funky replacement for Newton too?

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