Recent content by ymehuuh

Homework Statement An ideal monatomic gas expands isothermally from 0.590 m3 to 1.25 m3 at a constant temperature of 780 K. If the initial pressure is 1.20x10^5 Pa. (a) Find the work done on the gas. (b) Find the thermal energy transfer Q. (c) Find the change in the internal energy...

Ok...if that is so...then... 81g*4.190j/kg*Tf + 878g*4.19j/kg*Tf -91970.5 + 81*333 = 0 so Tf = 16.1757

So then it should be... 878*4.19*(Tf-25)+26973=0 Tf=17.668 That's not correct either...

Qmelt=81g*333j/g =26973 So... 878*4.19*(Tf-25)+81*2.09*(Tf-0)+26973=0 3848.11Tf=64997.5 Tf=16.89 Which is still wrong...what am I doing wrong now?

Homework Statement A 81-g ice cube at 0°C is placed in 878 g of water at 25°C. What is the final temperature of the mixture? Homework Equations No heat is loss therefore m*Cp*deltaT+m*Cp*deltaT=0 Cp ice=2.09 Cp water=4.19 The Attempt at a Solution...

Whoops...divided instead of multiplied. Thanks.

Homework Statement An aluminum rod is 23.0 cm long at 20°C and has a mass of 350 g. If 12500 J of energy is added to the rod by heat, what is the change in length of the rod? Answer is in mm Homework Equations Q=m*c*delta T deltaL=alpha*L0*deltaT alpha=24x10^-6 c=900j/kg The...

nm...it was just w=at

Homework Statement A large grinding wheel in the shape of a solid cylinder of radius 0.330 m is free to rotate on a frictionless, vertical axle. A constant tangential force of 270 N applied to its edge causes the wheel to have an angular acceleration of 0.984 rad/s2. If the wheel starts...

perfect! Thanks!

Oh, I reversed the two and that's why I got it wrong. Thanks. What would I use for part c?

Homework Statement Four objects are held in position at the corners of a rectangle by light rods as shown in the figure below. The mass values are given below. M1 (kg) M2 (kg) M3 (kg) M4 (kg) 3.50 1.50 3.90 1.70 (a) Find the moment of inertia of the system...

Figured it out. Used equation S=(v^2-u^2)/2a THANKS!

Find the height from which you would have to drop a ball so that it would have a speed of 5.9 m/s just before it hits the ground. vf=5.9 v0=0 Not sure what I can do with only this much information...

A daredevil on a motorcycle leaves the end of a ramp with a speed of 42.0 m/s as in the figure below. If his speed is 39.8 m/s when he reaches the peak of the path, what is the maximum height that he reaches? Ignore friction and air resistance. So v0=42.0m/s and vf=39.8m/s...what equation am...