Recent content by DeepPatel

Homework Statement A pendulum swings at 70 cycles per minute. a. What is the frequency in Hz? b. What is the period in seconds? Homework Equations T = 1 / f The Attempt at a Solution For part a) Used the answer for part b & I took the equation above, divided 1 by 1.167 cycles/second & got...

Homework Statement What is the power supplied by a 60.0 kg person running up a flight of stairs a vertical distance of 4.0 m in 4.2 s? m = 60kg d = 4m t = 4.2 Homework Equations P = W / t W = Fdcos(Θ) F = ma The Attempt at a Solution Combining the equations above I did (m) (a) (d) / (t) which...

Homework Statement A girl is cliff diving. She jumps (assume from rest) from an 80 meter high cliff. a) If her mass is 64 kg, and her body can only withstand a force of 11,000 N without breaking a bone, what is the minimum depth she must go into the water and not get hurt? b) If we assume she...

Yeah our teacher prefers we use 10 m/s2 instead of 9.81m/s2 to save us time and make it easier.

I had added 880J and I think I had to subtract. If I fixed the errors I now got an answer of 20.549 m/s (1/2)(75)(72) + (75)(10)(20) - 880 = 1/2 (75) (v2f)

The work done by friction was negative, yes.

I don't think it should but if the equation I have is correct I'm not sure where I am going wrong. Since it is asking for the speed at the bottom I do think it should have a higher speed.

Now I plug that into the original question 1/2mvi2+ mgh + W = 1/2mvf2, solve for final velocity and I got 21.66 m/s

So then work would be equal to 880J for part a.

Oh I forgot the angle is defined by the direction of the force and distance, in this case the force and distance are opposite to each other so would the angle be 180 degrees?

Did 22N*40m*cos(30) and got that.

Alright so knowing that using W=Fdcos(theta) I should get 762J. part b) If that is work then I can now solve for vf by using the original formula and get 427.32 m/s? Seems a bit large to me.

Sine is opposite over hypotenuse and we are giving the opposite which is 20m unless I am putting my angle in the wrong spot. Sin(30) is equal to 0.5 which means that x would have to be 40 which I calculated wrong in the first place.

Were all my units correct because the question asked for specifics and that is what confused me?

Yeah I did, the first time I did it I just did the sin(30) = 20/x and got 10 for x.