Answer:
C. 6km
Explanation:
Dolphin is travelling with an average velocity of 3 kmph. So 1 h = 3km
And 2 h = 3×2 = 6km.
The body systems that help cells get the energy they need are the digestive system and circulatory system. The first system is the digestive system because when you eat food, your body breaks it down using the stomach and other different parts of the digestive system. The next one is the circulatory system because your blood carries the nutrients you acquired from food you digested to the cells throughout your body.
The only thing we know of so far that can shift light to longer wavelengths is the "Doppler" effect. If the source and the observer are moving apart, then the observer sees wavelengths that are longer than they should be. If the source and the observer are moving toward each other, then the observer sees wavelengths that are shorter than they should be. It works for ANY wave ... sound, light, water etc. The trick is to know what the wavelength SHOULD be. If you know that, then you can tell whether you and the source are moving together or apart, and you can even tell how fast. If the lines in a star"s spectrum are at wavelengths that are too long, then from everything we know right now, the star and Earth are moving apart.
Answer:
--->
Explanation:
1. Air Resistance- this is a type of frictional force that acts upon objects as they travel through air. It usually opposes the motion of an object and it is mathematically difficult to predict its value.
2. Gravity- the force of gravity is the force that the earth, and moon use to attract an object towards itself. The moon has far less gravity than earth. All objects on earth experience a force of gravity that pulls them downward, towards the center of the earth.
3. Tension- the tension force is the force that is transmitted through a string, rope, cable or wire when it is pulled from opposite ends. The tension force is directed along the length of the wire and pulls equally on the objects on the opposite ends of the wire
4. Friction- this is the force exerted by a surface when an object moves across it. Friction results from the two surfaces being pressed together closely.
5. Electromagnetic force- although they don't seem similar, electricity and magnetism are related. Flowing electrons produce magnetism, and a moving magnet produces electricity.
6. Upthrust- this is the upward force that a liquid or gas exerts on a body floating in it.
7. Spring force- The spring force is the force exerted by a compressed spring upon any object that is attached to it. This object is always acted upon by a force that restores the object to its rest or equilibrium position.
8. Applied force- An applied force is a force that is applied to an object by a person or another object.
9. Electrostatic force- The types of forces exerted by all electrically charged bodies on another charged bodies in the universe are ‘electrostatic forces’. They can be either positively or negatively charged.
10. Nuclear force- these are the forces that act between two or more nucleons. They bind protons and neutrons into atomic nuclei. The nuclear force is about 10 millions times stronger than the chemical binding that holds atoms together in molecules.