How long must a simple pendulum be if it is to make exactly one swing per three seconds? (that is, one complete oscillation takes exactly 6.0

This is a physics question.

Use the formula for simple pendulum:

T = 2π √(L/g)

Where T is the period (time to complete a full oscilation), L is the lenght and g acceleration of gravity ≈ 9.81 m/s^2 .

So, solve for l:

√(L/g) = T / (2π)

L = [T / (2π) ] ^2 * g = [ 6.0s / (2π) ]^2 * 9.81 m/s^2 = 8.9 m

8.9 m

 The correct option is (B)

Step-by-step explanation:  We are given a right-angled triangle ABC, where AC is the hypotenuse and

We are to select the equation that could be used to find the measure of ∠B.

With respect to angle B,

perpendicular, AC = 3 units,  base, AB = 6 units  and  hypotenuse, BC = 3√5 units.

So, the sine and cosine of angle B can be written as

and

Thus, the correct equation that could be used to find the measure of ∠B is

Option (B) is CORRECT.