Saturday

October 25, 2014

October 25, 2014

Posted by **AP Physics** on Tuesday, June 16, 2009 at 7:28pm.

given that I person 65 kg takes 4.5 s to climb a flight of stairs that is 5.5 m

my question is well I was asked to solve for the work and

W=fd

and in this case f is equal to the normal force correct? Just take the opposite of mg???????

Also I'm asked to solve for PE and sense PE also equal mgh...

is PE the same as work in this situation????

a similar problem a person is running forwards on a flat surface or 5 m long with a mass of 65 kg and takes 1.75 s starting from rest

I'm asked to solve for the work done

sense F=ma

how do I find the acceleration???

My last question

I'm given a spring that has a mass of 100 g and a constant of 22 N/m with an A of 5 cm

I belive the A is amplitude

and I'm asked for the Total Energy which i don't know how to do

the max velocity also have no idea how to do

and the max force which i don't know how to do

THANK You

- AP Physics -
**Damon**, Tuesday, June 16, 2009 at 7:44pmAs for the stair problem, you have the right idea. The work, mgh, goes into increasing the potential energy.

- AP Physics -
**Damon**, Tuesday, June 16, 2009 at 7:46pmaccelerates starting from rest

d = (1/2) a t^2

5 meters = (1/2) a (1.75)^2

solve for a, the acceleration

- AP Physics -
**Damon**, Tuesday, June 16, 2009 at 7:53pmm = 100 grams = .1 kg

k = 22 N/m

A = 5 cm = .05 m

y = .05 sin w t

w = sqrt (k/m)

you could solve for w

then maximum stretch = .05 m and velocity is zero there so

Maximum potential energy = maximum energy = (1/2) k .05^2 (This is because the kinetic energy and velocity are zero when the spring is stretched maximum)

Max force = k A

to get maximum velocity

(1/2) m v^2 = max kinetic energy = max total energy = max potential energy which we know

- AP Physics -
**AP Physics**, Wednesday, June 17, 2009 at 1:46amThank You

**Answer this Question**

**Related Questions**

physical Science - Two people who weigh the same climb a flight of stairs. The ...

math - An elf has a staircase with 10 steps to climb. Each step it takes can ...

Physics ~please help me~ - 1.) Two people of the same mass climb the same flight...

math - An elf has a staircase with 10 steps to climb. Each step it takes can ...

Physics - Two People who weigh the same climb a flight of stairs. The 1st person...

Physics - Two People who weigh the same climb a flight of stairs. The 1st person...

physics - a person carries a 58kg package of books up a flight of stairs the ...

physics - A 680 newton student runs up a flight of stairs 3.5 m high in 11.4 ...

Physical Science - Two people who weigh the same climb a flight of stairs. The ...

science - How much work do you do when you climb a flight of stairs 4 m high? ...