If the object sinks, then it must be heavier than the weight of the water
it displaces ... heavier than the buoyant force acting on it.
If the buoyant force were equal or greater than the object's weight, then
the object would rise to the surface in water.
<span>When an observer is moving towards a stationary object making a sound,
he runs the risk of startling the stationary object.
On the other hand, if the stationary object is the one making the sound,
then the pitch of the sound perceived by the observer is higher than the
sound that the object is actually making.</span>
The average speed of the runner is 8.7m/s.
Therefore, Option C) 8.7m/s is the correct answer.
Given the data in the question;
Distance covered; 
Time taken; 
Average speed; 
Speed is the rate at which an object covers a certain distance. It is expressed as:
Where s is speed, d is distance and t is time taken.
We substitute our given distance into the equation
The average speed of the runner is 8.7m/s
Therefore, Option C) 8.7m/s is the correct answer.
Learn more: brainly.com/question/21503615
Mechanical weathering is the process of breaking big rocks into little ones. This process usually happens near the surface of the planet. Temperature also affects the land. The cool nights and hot days always cause things to expand and contract. That movement can cause rocks to crack and break apart.
Chemical weathering occurs when chemical reactions weaken and decompose rocks, often acting alongside the physical breakdown of rock, aka mechanical weathering. This process involves a chemical change, which actually alters the rock's or mineral's chemical composition.
<span>208.3 meters
The product of the wavelength multiplied by the frequency will equal the speed of light which is 299792458 m/s. Simple algebra will tell you that you can divide the speed of light by the frequency to get the wavelength. So
224997958 m/s / 1080000 1/s = 208.3314426 m
Rounding to 4 significant digits gives you 208.3 meters.</span>
