Raju and Ravi are standing on the opposite sides of a closed door, both of them are able to see each other clearly. Which type of substance is used to make this door?
A. Transparent
B. Translucent
C. Opaque
D. All the above

On mars a rock falls an unknown vertical distance from a resting position and lands in a crater. if it takes the rock 2.5 seconds to fall, how high is the cliff the rock fell from? mars' surface gravity is 3.8 m/s2.

Astep up transformer has 250 turns on its primary and 500 turns on it secondary. when the primary is connected to a 200 v and the secondary is connected to a floodlight that draws 5a, what is the power output? show all of your work.

Hydroelectricity provides about 7 percent of the electricity generated in the united states. (a) explain how a hydroelectric power plant converts energy stored in water into electricity. (b) identify two factors that determine the amount of electricity that can be generated by an individual hydroelectricity power plant. (c) describe the two main types of land-based hydroelectric power plants. (d) describe two economic advantages and two environmental disadvantages of hydroelectricity.