Why do trucks need a runaway ramp

The slope of a velocity time graph over any interval of time gives the during that interval

Calculate the numbers of photons having a wavelength of 10.0 mm required to produce 1.0 kj of energycalculate the numbers of photons having a wavelength of 10.0 mm required to produce 1.0 kj of energy

The frequency of a tuning fork can be found by the method shown. a long tube open at both ends is submerged in a beaker of water, and the vibrating tuning fork is placed near the top of the tube. the length l of the air column is adjusted by moving the tube vertically. the sound waves generated by the fork are reinforced when the length of the air column corresponds to one of the resonant frequencies of the tube. the smallest value for l for which a peak occurs in sound intensity is 7 cm. l what is the frequency of the tuning fork? the speed of sound in air is 345 m/s. answer in units of hz