brickman7713

Nope that is all I know from the question. Yeah I was wondering why I had three numbers and only needed two lol.

I am lost on this. I know the equation 1/DI + 1/DO = 1/F but I don't know how it applies to this. Thanks A 1.9 cm-tall object stands in front of a converging lens. It is desired that a virtual image 2.7 times larger than the object be formed by the lens. How far from the lens (in cm) must the object be placed to accomplish this task, if the final image is located 10 cm from the lens?

Okay so it's just 1540/11 million. Got it, thanks!

I do now, figured it out, thanks!

Sorry the post submitted before I finished, this is the question. An audio speaker producing a steady sound at an outdoor concert is 42 ft away from you. If you move to a position where the speaker is 70 ft distant, by what factor will the amplitude of the sound change?

Ultrasound probes can resolve structural details with sizes approximately equal to the wavelength of the ultrasound waves themselves. What is the size of the smallest feature observable in human tissue when examined with 11-MHz ultrasound? The speed of sound in human tissue is 1,540 m/s. Thanks!

I am clueless on this one.

Ok, that was an online tool. How does converting a mass that is solid to a liter that is liquid work?

Is it 45.48 liters in volume then?

I assume earth so 9.8 is what I think you are referring to. 38.75kg ?

Ok but how? I know the mass density is 8,930 kg/m3 and the weight density is 557 lb/ft3 and of course weight of 380 newtons.

Ok so how would I do that, Do I need to find the size of the object?

A scale reads 380 N when a piece of copper is hanging from it. What does it read (in N) when it is lowered so that the copper is submerged in water? I need to find out the mass of the copper right to know how much water it displaced then take the 380 minus the weight of that water?

Ok, thanks for the help!

Oh I get it, it's just the weight of the displaced liquid divided by the weight density. Am I allowed to post the answer like that here?