Recent content by shakejuhn

Homework Statement The photoelectric threshold wavelength of a tungsten surface is 272nm A) what is the threshold frequency of this tungsten b) what is the work function in electonVolts of this tungsten C) Calculate the maximum kinetic energy in eV of the electrons ejected from this...

Homework Statement How fast would a 4.54g bullet have to be traveling so that it increased the temperature of 1.00 L of water by 1.30oC if it gave all of its kinetic energy to the water? Homework Equations i don't know what equation to use i have two of them but its seems they don't...

i just said find the answer in joules

Homework Statement How much heat is required to raise the temperature of 0.250kg of water from 20.0oC to 30.0oC? If this amount of heat is added to an equal mass of mercury that is initially at 20.0oC, what is its final temperature? Homework Equations Q=c*M*(t2-t1) The Attempt...

ok so the equation would look like this M(9.8)(100) = mc Delta T but i still need to know the Mass and MC am i overlooking something??

ok so P.E.=MGH P.E. = M(9.8)(100) is this correct there are still 2 unknows

Homework Statement Much of the energy of falling water in a waterfall is converted into heat. If all the mechanical energy is converted into heat that stays in the water, how much of a rise in temperature occurs in a 100 m waterfall? Homework Equations q=mc(Tf-Ti) Q=mc Delta T Delta...

Homework Statement You throw a 25.0N rock into the air from ground level and observe that, when it is 13.0m high, it is traveling upward at 21.0m/s A. Use the work-energy principle to find the rock's speed just as it left the ground. B. Use the work-energy principle to find the maximum...

ok so i have Fnet=M*a so for the tension on the rock i have a tension and a weight soball \/ t1 | | /\ t1 so would this be the correct equation to solve for T if it is what would the acceleration be because its not give or i don't think there is anyway to find it T1=313.6 * A

Ok here the problem i need to find the tension of the three wires but I am very lost and don't know where to start or how to finish. so for i got 32*98 = 313.6N i don't know what to do next can someone please lead me in the correct direction to solve the problem.

ok i got it i figured it out i had to use a seperat equation where X=Vot + .5(a)(t)^2 x=0(6)+ .5(4.47)(6)^2 solve all that for X and i got 80.46 m and this answer is correct.

Calculate distance from force HELP! In outer space, a constant net force of magnitude 135N is exerted on a 30.2kg probe initially at rest. What acceleration does this force produce? How far does the probe travel in 6.00s what i have so far is that F=Ma where the force is 135N=30.2a solve...

ok so if i go W= F * S i get W= 76* 4.35*10^-5 is this setup correct?

i still confused, i use teh formula F=MA where M= 4.35*10^-5 what would A be, it says that the drop fall at a constant speed.

it does not say what work is. its a 2 part problem. i know first i must find the work done by gravity after the drop has fallen 76m after i find that i use the information i found to find J done by air resistance. i hope this makes it a little bit clearer so i can get some kind of help...