A classic:Rates of change ploxx
maths teachers NEED better laddersA classic:
Consider a 3m ladder leaned up against a wall at an angle of 60 degrees from the floor.
It slides down slowly at a rate of 1cm/second.
When the angle is less than 40 degrees, the weight of the person standing on it will overcome the friction holding the ladder up against the wall, and it will fall/collapse completely.
It takes 5 seconds for somebody to get off the ladder.
If a person stands on the ladder when it is at 60 degrees from the floor, how long (in seconds) do they have to stand on the ladder before it becomes dangerous to stand on?
Haha I am very confused.maths teachers NEED better ladders
I have no idea what to do lol, i found dx/dt given dy/dt = 1A classic:
Consider a 3m ladder leaned up against a wall at an angle of 60 degrees from the floor.
It slides down slowly at a rate of 1cm/second.
When the angle is less than 40 degrees, the weight of the person standing on it will overcome the friction holding the ladder up against the wall, and it will fall/collapse completely.
It takes 5 seconds for somebody to get off the ladder.
If a person stands on the ladder when it is at 60 degrees from the floor, how long (in seconds) do they have to stand on the ladder before it becomes dangerous to stand on?
what I picture in my mind when I see the word 'ladder'Haha I am very confused.
Ladder + wall = right-angled trianglewhat I picture in my mind when I see the word 'ladder'
when was the last time you've seen one of these:
I guess one could make a somewhat a variation of the question, using the 1st one
Yeah, I used a long method that involved differentiating stuff and then integrating some different stuff... Only to realise I could've done it with basic geometry. Got the same answer both ways though, so maybe it is right.^ That's what I got I didn't even end up using calculus.
how did u do it i dont understand what its asking for min time?^ That's what I got I didn't even end up using calculus.
John Fitzpatrick 3 Unite Mathematics
25(C)
A particle is moving in a straight line. If x is its displacement at time t and v^2=5(4-x^2) Find the acceleration in terms of x only, Show that the motion is simple harmonic and find its period and amplitude.