Questions

[slanders09]

27) A clock face reads exactly 3:45. How long will it take the minute hand to align with the hour hand? (min)


58) Ten people in a community came down sick. The disease spread such that the number of ill people doubled every 4 days. After what time was the rate of disease contraction 100 people/day? (days)


66) Casey stands on the roof of a building at 125ft above the ground. He tosses a ball off the roof with an initial velocity of 20mph. At what angle (straight out is 0, straight up is 90) must he toss the ball if it hits the ground in exactly 3.5 sec? (deg)

[bradp]

27) the hands will align between 4:20 and 4:25
to find that time specifically, do minute hand = hour hand with this:
[unparseable or potentially dangerous latex formula] where t is the time in hours after 4:00....

58) [unparseable or potentially dangerous latex formula]
[unparseable or potentially dangerous latex formula]
[unparseable or potentially dangerous latex formula]

find [unparseable or potentially dangerous latex formula] and set it equal to 100

66) [unparseable or potentially dangerous latex formula]
[unparseable or potentially dangerous latex formula]

[Quelloquialism]

[slanders09]

yeah, the official answers are:

27) 36.8

58) 41.7 days

66) 44.6 deg

...thanks!

[Quelloquialism]

I've reworked it a few times, and I can't get anything other than 23.4 on #58. Maybe I'm missing something?

[AuSmith]

[slanders09]

okay....i went back and looked at the test. the question states "100 people/HOUR"

my bad

[Quelloquialism]

If that's the case, do a quick unit conversion: 100 people/hour * 24 hours/day = 2400 people/day, and plug it back in. The only difference between this way and the other is that you're setting the derivative equal to 2400 instead of 100; after that first step of simplifying the equation, it'll turn into 960 instead of 40. And that does get you 41.7, as far as I can tell.

[AuSmith]