25 equals 1/2×2× V squared

Plss anybody know how to do this? ? i need the answers from a through d

Apulley with a mechanical advantage of 5 will require you to pull times the amount of rope. a. 1/5 b. 5 c. 10 d. 15

Solar cell a produces 100 joules of energy, when a light source is shown on it for 3 minutes. solar cell b produces 200 joules of energy when the same light source is shown on it for 5 minutes. which solar cell works better? a) solar cell b, because it produces more energy. b) solar cell b, because it generates more power. c) solar cell a, because it produces energy quicker. d) solar cell a, because it generates a greater wattage. eliminate