Do swimming which make Newtons Third Law
Acceleration is the rate of change of velocity as a function of time. For example a car traveling at 50 km/hr starts to accelerate, 10 seconds after, its speed changes to 100 km/hr then the acceleration of the car during the time can be calculated as below: initial speed = 50 km/hr.
The equation of motion of a pendulum is:

where
it its length and
is the gravitational acceleration. Notice that the mass is absent from the equation! This is quite hard to solve, but for <em>small</em> angles (
), we can use:

Additionally, let us define:

We can now write:

The solution to this differential equation is:

where
and
are constants to be determined using the initial conditions. Notice that they will not have any influence on the period, since it is given simply by:

This justifies that the period depends only on the pendulum's length.
Answer:
T=189.15 N
Explanation:
As we know that for downward motion
F acting = F (weight) - Tension T
m a = mg - T
⇒ T = m (g - a)
T = 29.1 kg ( 9.8 m/s² - 3.3 m/s²)
T=189.15 N