Prominences and sunspots are both: A. Jets of burning gas

B. Patches on the Sun's surface

C. Influenced by the Sun's electromagnetic field

D. Visible during an eclipse

Ablock of mass m = 2.5 kg is attached to a spring with spring constant k = 710 n/m. it is initially at rest on an inclined plane that is at an angle of θ = 23° with respect to the horizontal, and the coefficient of kinetic friction between the block and the plane is μk = 0.19. in the initial position, where the spring is compressed by a distance of d = 0.16 m, the mass is at its lowest position and the spring is compressed the maximum amount. take the initial gravitational energy of the block as zero. a) what is the block's initial mechanical energy? b) if the spring pushes the block up the incline, what distance, l, in meters will the block travel before coming to rest? the spring remains attached to both the block and the fixed wall throughout its motion.

1point) a skydiver weighing 130 lb (including equipment) falls vertically downward from an altitude of 14,000 ft and opens the parachute after 20 s of free fall. assume that the force of air resistance, which is directed opposite to the velocity, is of magnitude 0.85|v|0.85|v| when the parachute is closed and is of magnitude 17|v|17|v| when the parachute is open, where the velocity vv is measured in ft/s. assume that acceleration due to gravity has magnitude 32 ft/s/s; remember that weight is the product of mass and gravitational acceleration. find the speed of the skydiver when the parachute opens. speed is 150.6121788 ft/s find the skydiver's height when the parachute opens. height is 2338.98591 ft find the limiting velocity vlvl after the parachute opens. (think about whether this should be positive or negative.) vl=vl= 7.647 ft/s

Question 1 what is amperage? is the rate of doing work. is the rate of flow of protons in electric current. represents the amount of pressure behind electron flow. is the rate of flow of electrons in electric current. 2 points question 2 what is voltage? is the rate of doing power. represents the amount of pressure behind electron flow. is the rate of doing work. is the rate of flow of electrons in electric current. 2 points question 3 what is power? is the rate of flow of protons in electric current. is the rate of flow of electrons in electric current. is the rate of doing work. represents the amount of pressure behind electron flow. 2 points question 4 if we multiply volts times amps we get what? power circuit work current 2 points question 5 what are two ways alternating currents are similiar? in both ac and dc electrons flow in the same pattern. in both ac and dc, the flow of electrons changes directions back and forth. both ac and dc are only possible in certain materials with atoms that will allow electron flow. both ac and dc involve the flow of electrons. 4 points question 6 how does the flow of electrons flow in an alternating current? the flow of electrons is always slower in an alternating current than within a direct current. the flow of electrons is not constant and forward; it changes direction back and forth. electrons flow from from a higher affinity to that of a lower affinity. electron flow is constant and only in a forward direction. 2 points question 7 what is the flow like in a direct current? the flow of electrons is not constant and forward; it changes direction back and forth. the flow of electrons is constant and only in a forward direction. the flow of electrons go from a higher affinity to a lower affinity. the flow of electrons are always faster in a direct current. 2 points question 8 how is an electric current able to flow? electrons flow from the higher affinity to lower affinity and electrical current is generated. protons flow from the higher affinity to lower affinity and electrical current is generated. the movement of protons from one atom to another leads to an electric charge. the movement of electrons from one atom to another atom in a line results in a flow of electric current. 2 points question 9 how do electrons move from the two different types of metal in a battery? protons flow from the metal with the lower affinity to the metal with higher affinity and electrical current is generated. electrons flow from the metal with the lower affinity to the metal with higher affinity and electrical current is generated. electrons flow from the metal with the higher affinity to the metal with lower affinity and electrical current is generated. protons flow from the metal with the higher affinity to the metal with lower affinity and electrical current is generated.