Recent content by hodgepodge

thanks

so, is it right?

Homework Statement A person accidentally bit his tongue and wants to examine the bite by using a concave mirror. The mirror is placed 10 cm from the bite with the result that a virtual image of the bite appears 4 times actual size. Find the parameters s (distance from object to mirror), s'...

ah-ha answer = 10 log (r^2/R^2) = 10 log ( 30^2 / 150^2) = -13.9794 dB am i supposed to put 150^2/30^2 in the log, or is it fine the way it is? thanks

Homework Statement A train is traveling 30 m/s in still air. The frequency of the train whistle is f = 250 Hz. What frequency is head by a passenger on a train moving in the opposite direction at 18 m/s and approaching the first train? The velocity of sound in air is 344 m/s. Homework...

yeah, the powers cancel out, but how does 30 cm and 150 cm relate to area so far i have answer =10 log (A * 1/A)

u divide them, i understand that, however but where does the distance come into play? in the area?

Homework Statement A baby's mouth is 30 cm from her father's ear and 150 cm from her mother's ear. Compute the difference, in dB, between the sound intensity levels heard by the father and by the mother. Homework Equations Intensity = Power/ Area; power = 1/2 * mass per unit...

werd, thanks

bump to the top i need to know what if i did anything wrong, or if the book is wrong

Homework Statement Two slits are separated by 0.260 mm. A beam of 500 nm light strikes the slits, producing an interference pattern. Determine the number of maxima observed in the angular range -31.0° < θ < +31.0°. Homework Equations i used dsinθ = m(lambda) The Attempt at a...

Homework Statement A block slides on a rough horizontal surface from point A to point B with a force of magnitude 2 Newtons acts on the block between points A and B. Points A and B are 1.5m apart. If the KE of the block at A is 5 joules, and KE at B is 4J, how much work is done on the block...

Thank you so much.

so i could just take the derivative and find instantaneous velocity and then take second derivative for instantaneous acceleration?

Homework Statement a body oscillates with simple harmonic motion along the x axis. Its displacement varies with time according to the equation x=5.0 sin (pi*(t) + pi/3). What is the velocity in m/s and acceleration in m/s^2 of the body at t=1.0s? Homework Equations x(t) = A cos...