a stone of mass 50g projected vertically upwards from the ground acquires a velocity of 12ms at a height of 20m. the initial k. e of the stone is? the maximum height attached by the stone is?​

Starting with only the balmer series light (visible light), how could we ensure that the solar panels generate a current that mark can use for his power station? a)by gradually increasing the brightness (amount) of light that we shine on it. b)by gradually increasing the frequency of the light we shine on it. c)by gradually increasing the wavelength of the light that we shine on it.

Two resistors r1 and r2 may be connected either in series or parallel across an ideal battery with emf ε. we desire the rate of energy dissipation of the parallel combination to be 8.75 times that of the series combination. if r1 = 105 ω, what are the (a) smaller and (b) larger of the two values of r2 that result in that dissipation rate?

You have 80 g of 60oc water and 80 g or 10oc water. what is the final temperature when the two are mixed? explain.