Multi-Choice! A gold pendulum swings with angular acceleration a, and a point on the edge has tangential acceleration a. A silver pendulum swings with angular acceleration 3a, and a point on the edge has tangential acceleration 5a. How does the radius of the gold pendulum r gold compare with the silver pendulum r silver ?

A 1/15
B 5/3
C 15
D 3/5​​

Asheet of steel 1.5 mm thick has nitrogen atmospheres on both sides at 1200oc and is permitted to achieve a steady-state diffusion condition. the diffusion coefficient for nitrogen in steel at this temperature is 6 x 10- 11 m2 /s, and the diffusion flux is found to be 1.2 x 10-7 kg/m2 -s. also, it is known that the concentration of nitrogen in the steel at the high-pressure surface is 4 kg/m3 . how far into the sheet from this high-pressure side will the concentration be 2.0 kg/m3 ? assume a linear concentration profile.

The number of passengers who arrive at the platform of a subway station for the 10 am train is a random variable with a mean of 120 and a variance of 16. find the lower bound of the probability that there will be between 100 and 140 passengers (round off to second decimal place).

Explain what it means to view something from a frame of reference. provide an example that illustrates your explanation. (4 points)