11. a 2 - kilogram rock is dropped from a height of 10 meters. what is the kinetic energy of the rock at the…

11. a 2 - kilogram rock is dropped from a height of 10 meters. what is the kinetic energy of the rock at the lowest point just before it hits the ground? ignore air resistance.\n0 j\n20 j\n98 j\n196 j\nclear all

11. a 2 - kilogram rock is dropped from a height of 10 meters. what is the kinetic energy of the rock at the lowest point just before it hits the ground? ignore air resistance.\n0 j\n20 j\n98 j\n196 j\nclear all

Answer

Explanation:

Step1: Apply energy - conservation

The initial potential energy of the rock at height (h) is converted into kinetic energy (K) just before hitting the ground. The formula for gravitational potential energy is (U = mgh), where (m) is mass, (g) is the acceleration due to gravity ((g=9.8\ m/s^{2})), and (h) is height.

Step2: Calculate potential energy

Given (m = 2\ kg), (g = 9.8\ m/s^{2}), and (h = 10\ m). Substitute these values into the formula (U=mgh). So (U=2\times9.8\times10). [U = 196\ J] Since (K = U) (by conservation of mechanical energy, ignoring air - resistance), the kinetic energy just before hitting the ground is also (196\ J).

Answer:

196 J