A valve is a flap of tissue that prevents blood from flowing back
Answer:
In a collision, the velocity change is always computed by subtracting the initial velocity value from the final velocity value. If an object is moving in one direction before a collision and rebounds or somehow changes direction, then its velocity after the collision has the opposite direction as before.
Explanation:
Answer:
(C) length / height of the plane
Explanation:
The mechanical advantage of an inclined plane can be determined using different variables. In this case, the geometry of the setup is relevant. The advantage is proportional to the length of the plane, and inversely proportional to the height: it is the ratio (length) / (height) of the plane. For example, given a desired, fixed height, a long inclined plane gives you a bigger mechanical advantage than a short inclined plane. In this example, pushing an object up the long plane will require a smaller force, than it would on the short plane.
Strictly speaking, (D) would also "allow you to determine the mechanical advantage" because you could simply invert the ratio listed under (D). However, (C) is the best, direct, answer.
Answer: The ability to move or change an object or what a wave carries is called Energy
Explanation: Waves are disturbances in physical quantities. Example of waves are light waves, sound waves, or transverse oscillations of a string. These disturbances use energy to create and propagate, for it to move the constituent particles or change the electric or magnetic fields. Therefore, power of a wave is therefore, energy transported divided by unit time caused by the oscillations of a particular wave. The derivation of a formula for the power depends on the medium -- for light waves, the power is measured by the pointing vector, whereas for oscillations on a string, the power can be computed directly by balancing forces through the application of newton law. However, for all types of waves, the formula and physical meaning of the power takes similar forms, typically depending on the square amplitude of the waves among other factors.
