Recent content by Lyphta

Homework Statement What are the wavelengths in air of the lowest and highest audible frequencies if te range of human hearing is 20 Hz to 20 kHz and the sped of sound is 342 m/s? Homework Equations v= \lambdaf The Attempt at a Solution v= \lambdaf 342 = 20 Hz \lambda \lambda = 17.1...

Homework Statement While standing on a long board resting on a scaffold, a 70 kg painter paints the side of a house. If the mass of the board is 15 kg, how close to end can the painter stand without tipping the board over? http://img146.imageshack.us/my.php?image=physicssl9.jpg Homework...

Homework Statement A wheel initially rotates counterclockwise about a fixed axis, with an initial angular speed of 1.2 radians per second. If it accelerates uniformly to 2.0 radians per second clockwise during a 5 second interval, what is the magnitude of its displacement during this...

oh yeah i got it! thanks!

i know that stuff on the website. the only thing i don't understand is how to apply it to part b and d because I'm not sure of how to convert them into minutes. and without that, i can't figure out how to find the velocity...

[SOLVED] Gravitational Forces Homework Statement A 1000 kg weather satellite is orbiting the Earth at a constant speed. It is 500 km above the Earth's surface. The Earth has a mass of 5.976 x 10^24 kg and a radius of 6370 km. (a) How much gravitational force exists between the Earth and the...

Homework Statement Imagine that you swing about your head a .250 kg ball attached to the end of a string. The ball moves at a constant speed in a horizontal circle with a radius of 1.50 m. If it takes 1.20 seconds for the ball the make one revolution, (a)what is the ball's tangential speed...

Homework Statement A 90-g ball moving at 100 cm/s collides head-on with a stationary 10-g ball. Determine the speed of each after impact if (a) they stick together, (b) the collision is perfectly elastic.Homework Equations p=mvThe Attempt at a Solution I already solved A, but I don't know how...

by u, do you mean initial velocity? or potential energy?

Homework Statement A 3250 km aircraft takes 12.5 minutes to achieve its cruising altitude of 10 km and cruising speed of 850 km/h. If the plane's engines deliver, on the average, 1500 hp of power during this time, what is the efficiency of the engines? Homework Equations Efficiency =...

Homework Statement When a 75 gram mass is suspended from a vertical spring, the spring is stretched from a length of 4.0 cm to a length of 7.0 cm. If the mass is then pulled downward an additional 10.0 cm, what is the total work done against the spring force?Homework Equations U=mgh (Don't need...