Q. A beam resting on two pivots has a length of L = 6.00m and mass M = 107.4 kg. The pivot under the left end exerts a normal force n1 on the beam, and the second pivot placed a distance l = 4.00m from the left end exerts a normal force n2. A woman of mass m = 60.7 kg steps onto the left end of the beam and begins walking to the right. The goal is to find the woman's position when the beam begins to tip.
Q. Suppose that the microwave radiation has a wavelength of 11.2 cm. How many photons are required to heat 235 mL of coffee from 25.0 ^circ rm C to 62.0 ^circ rm C? Assume that the coffee has the same density, 0.997 g/mL, and specific heat capacity, 4.184 rm J/(gcdot K), as water over this temperature range.
Express the number of photons numerically.