Question

You wish to determine the density of a fluid substance you brought back to Earth after exploring planet Uzaz. You find a string and an object of known mass m = 7 kg, put a tub of water (total mass 10 kg) on a scale, and conduct two related experiments:

• Leaving the tub of water on the scale, you hang the object at the end of the string fully submerged in the water, and the scale now reads 150 N.

• Replacing the water with the new substance (still total mass 10 kg), you hang the object at the end of the string fully submerged in the new substance, and the scale now reads 135 N.

  (a) (5 points) Find the density of the new substance.

  (b) (4 points) (This has nothing to do with the substance from Uzaz.) The rod-and- ball object from question 6 hangs vertically down. With what frequency will it make small-amplitude pendulum oscillations?

Answer 1