Answer : Option C) copy the movements performed during the activity.
Explanation : Arm circles are an effective dynamic stretch for swimmers because they copy the movements performed during the activity.
During swimming when the arm circles are performed it stretches the triceps brachii, loosens the shoulder blade and stretches the side muscles.
Often many people are observed to perform this arm circles stretch without bringing the elbow behind the head, but especially for swimmers, this increases the stretching length and reduces stress while swimming.
Both the effects (l<span>engthening of the transmitted signal's wavelength and decrease in its frequency) indicates that the object is moving away from the observer, and this phenomenon is called Doppler effect.
In fact, when the object is moving away from the observer, the relative distance between two consecutive crests of the wave emitted by the object increases to the observer eyes, since he's moving away. This means that the wavelength appears larger, and since the frequency is inversely proportional to the wavelength, the frequency appears smaller.</span>
Answer:
The net force is 392N, pointing down.
Explanation:
The net force is the sum of all forces acting on the rock, namely the gravity ("+" acting downward) and the friction force due to air resistance ("-" acting upward):
The net force is 392N and pointing down (positive)/
Well, I may not know the exact answer, but I can confirm because of mass. The more mass an object has, the less control you have on it, so it can't be stopped easily. Let's take a small rock and a boulder for example. When a small rock rolls on the ground, it can easily be stopped by your hand or foot. But when you have to deal with an enormous boulder, you can't easily stop it with one just person. You'll need more people. So the answer is because the smaller vehicle has a lesser mass than the larger vehicle. (if you are looking for the answer, just look at the end.
