What is the acceleration acting on a grandfather clock's pendulum, of length 0.9m, with a maximum angular displacement of 0.1rad?

To find the acceleration acting on a grandfather clock's pendulum, we can use the formula for angular acceleration:

angular acceleration (α) = (angular displacement (θ) / time taken (t))^2

In this case, we are given the length of the pendulum (L = 0.9m) and the maximum angular displacement (θ = 0.1rad).

The time taken is not explicitly given in the question. However, if we assume that the maximum angular displacement occurs at the extreme ends of the swing (i.e., when the pendulum reaches its highest and lowest points), we can calculate the time period (T) using the formula:

T = 2π * √(L / g)

where g is the acceleration due to gravity (approximately 9.8 m/s^2).

Substituting the given values, we can calculate T:

T = 2π * √(0.9 / 9.8) ≈ 2.85 seconds

Now that we have the time period, we can calculate the angular acceleration:

angular acceleration (α) = (0.1 / 2.85)^2 ≈ 0.001

Therefore, the acceleration acting on the grandfather clock's pendulum is approximately 0.001 rad/s^2.