Recent content by linhy

in the xy-plan, line t passes through the origin and is perpendicular to the line 4x+y= k, where k is a constant. If the two lines intersect at the point (t, t+1). WHat is the value of t? What is t, and t+1? I know that y= -4x +k and perpendicular to that would be y=(1/4)x+k but where...

well.. it looks reasonable to me too? thx! ^_^

so i have D= (1/2)gt^2... i solved for t and i got 6.93 second it took for the stone to get up. Then I used V = D/T .. so T = D/V.. hence.. afterward i got .695.. so i add the two answers i got together ...and got 7.623s. Does this answer sound resonable?

Homework Statement one last problem.. IF you dropped a stone into a mine shaft that is 240 m deep. HOw soon after you drop the stone do you hear it hit the bottom of the shaft? Assume that temperature for this situation is 23.5 celcius Homework Equations So.. in order to get the...

once again, thx!

the number of waves that pass a given point each second. Is it another term of saying wave? vibration = wave? So.. 300waves/ 2.5 second = that means each second there is 120 waves? so.. 120 Hz?

Homework Statement a stringed musical intstrument from a remote tribe in Africa sets up a standing wave along the .75 m length of the string. This length corresponds to the distance between the first node and the seocnd node. The string has a mass of 11.5 grams. The strings vibrates 300 times...

thanks for the help.

which means that.. they can't simultaneously see and hear because sound wave (longitudinal wave)travels much slower than transverse wave...?

Homework Statement In a star Trek episode, a space station orbiting a planet blows up. The chew of the Enterprise simultaneously hears and see the explosion; they realized that tehre is no chance for rescue. If you have been hired a consultant, what two physics errors would you have found and...

Homework Statement a 25 kg block of ice is heated from -10 celcius to 78 celcius. HOw much heat is required.Homework Equations The Attempt at a Solution