Answer:
7.50 m/s^2
Explanation:
The period of a pendulum is given by:
(1)
where
L = 0.600 m is the length of the pendulum
g = ? is the acceleration due to gravity
In this problem, we can find the period T. In fact, the frequency is equal to the number of oscillations per second, so:

And the period is the reciprocal of the frequency:

And by using this into eq.(1), we can find the value of g:

Answer:
the horizontal distance covered by the cannonball before it hits the ground is 327.5 m
Explanation:
Given;
height of the cliff, h = 210 m
initial horizontal velocity of the cannonball, Ux = 50 m/s
initial vertical velocity of the cannonball, Uy = 0
The time for the cannonball to reach the ground is calculated as;
The horizontal distance covered by the cannonball before it hits the ground is calculated as;

Therefore, the horizontal distance covered by the cannonball before it hits the ground is 327.5 m