The speed of the wave is given by Distance divided by time.
Speed = 10.9/5.1
= 2.14 m/s
But; speed is also given by frequency multiplied by wavelength
Wavelength is 4 m( distance between two successive crests)
thus; 2.14 = 4 × f
f = 2.14/4
= 0.535 Hz
Answer:
A. 49 joules
Step By Step Solution:
Via kinematic equations we can must first determine the velocity of this object after 10 meters (since halfway of 20 meters is 10).

Where the initial velocity is zero since it's held at a height of 20 meters, hence it's not moving initially, g is the average gravity on Earth 9.8 m/s^2 and d is the distance this object will travel so 10 meters. By plugging these values in we obtain:

And the equation for kinetic energy is :

So the kinetic energy halfway after being released is 49 joules.
Answer:
Since the gravitational force is directly proportional to the mass of both interacting objects, more massive objects will attract each other with a greater gravitational force. So as the mass of either object increases, the force of gravitational attraction between them also increases.
Magnet
mixture
this text is just so I can use up twenty characters to post the answer