# Search results

1. ### General algebra-

Homework Statement Hi- this is actually part of my physics homework, but all I need help with deals strictly with algebra. This is my equation: (0.97)(1 + Beta gas (-Ti)) = (1 + Beta steel (-Ti)) Homework Equations The Attempt at a Solution How do I solve for Ti...
2. ### Ideal gas law-

Homework Statement A child holding a helium filled balloon @ sea level (T= 20 C) lets go of the string. The balloon rises freely several thousand meters, where T = 5 C and P = 0.70 atm. Find the percentage change in the balloon's volume. Homework Equations PV = nRT percentage...
3. ### Ideal Gas Law- finding gas density

Homework Statement What is the density of radon gas at 0 degrees C and 1 atmosphere? Homework Equations PV= nRT 0 C = 273 K density = mass/volume g/m^3 The Attempt at a Solution I want density = g/m^3 Below are the units of PV = nRT. I thought that breaking it down...
4. ### Simple Harmonic Motion- From Uniform Circular Motion

Homework Statement I don't have a homework question exactly, but I need help with an equation please. Angular frequency: W= 2 pi/T = 2(pi)(f) f= frequency And- W = square root of (k/m) k = spring constant m= mass So, wouldn't T = 2 pi / square root of (k/m) ?? My...
5. ### Angular velocity- pendulums and ideal springs

Homework Statement Suppose you were kidnapped and held prisoner by space invaders in a completely isolated room, with nothing but a watch and a pair of shoes (with shoelaces of known length). Explain how you might determine whether this room is on earth or on the moon. Homework Equations...
6. ### Simple Harmonic Motion and the Reference Circle

Homework Statement A loudspeaker diaphragm is producing a sound for 2.5 s by moving back and forth in simple harmonic motion. The angular frequency of the motion is 7.54 x 10^4 rad/s. How many times does the diaphragm move back and forth? Homework Equations angular freq. (W for...
7. ### Buoyancy of a raft

Homework Statement A raft is made of 11 logs lashed together. They are 38.0 cm in diameter and 6.10 m long and has a density of 700 kg/m^3. How many 60 kg persons can the raft hold in freshwater while keeping everybody's feet dry? Homework Equations Volume immersed/Volume total =...
8. ### Bouyant force and apparent weight

Homework Statement This question is continued from a problem that I have already solved. This is what I know from the previous problem that will be helpful: r= 0.20 m roh of solid sphere= 850 kg/m^3 mass sphere= 3.94 x 10 ^-5 kg I also have 2 apparent weights that I solved for when...
9. ### Angle Ratios

Homework Statement Tree A is 10 m tall. Tree B is 60 m tall. You're standing on level ground at a position that is 25 m from tree A and 75 m from tree B. You're eye height is 1.5 m above the ground. Find the ratio of theta B/ theta A, of the angles (measured from the horizontal) at which you...
10. ### Electric circuits

Homework Statement The power rating of a 1000-W heater specifies the power consumed when the heater is connected dto an AC voltage of 120 V. Explain why the power consumed by two of these heaters connected in series with a voltage of 120 V is not 2000-W. Homework Equations P= (V)^2/R...
11. ### Thermal Expansion

Homework Statement A hollow glass block is floating in a container of methyl alcohol. Initially, everything is at a temperature of 20 degrees C, and just 7% of the block is above the suface of the alcohol. If you heat the container (gently and evenly- so that everything warms up together)...
12. ### Fluids: Buoyancy

Homework Statement Using Archimedes' Principle and the diagram shown: (diagram is a "mass" of something in a liquid with an immersed portion (Vb) and an Un-immersed portion (Va)). A. prove that if an object is floating in a liquid, the fraction of the object's total volume that is...
13. ### Continuity: Constant mass flow rate

Homework Statement The aorta carries blood away from the heart at a speed of about 40 cm/s and has a radius of approx. 1.1cm. The aorta branches eventually into a large number of tiny capillaries that distribute the blood to the various body organs. In a capillary, the blood speed is approx...
14. ### Direction of Tension Forces

Hi there, Im working on a problem where a portion of it deals with tension. When making a force diagram, I have a difficult time figuring out which direction the tension force is pointing. The problem looks like this: A block on an incline going downhill to the right, with a string...
15. ### Work and Energy of an extreme skier

Hey, I have a question that I can't seem to work out...can anybody please help me?! Question: An extreme skier, starting from rest, coasts down a mountain slope that makes an angle of 25 degrees with the horizontal. The coefficient of kinetic friction between her skis and the snow is...