Energy flow in an ecosystem is best represented by a. the predator/prey relationship
b. food chains
C. food webs
d. autotrophs

Acave rescue team lifts an injured spelunker directly upward and out of a sinkhole by means of a motor-driven cable. the lift is performed in three stages, each requiring a vertical distance of 11.0 m: (a) the initially stationary spelunker is accelerated to a speed of 4.80 m/s; (b) he is then lifted at the constant speed of 4.80 m/s; (c) finally he is decelerated to zero speed. how much work is done on the 78.0 kg rescue by the force lifting him during each stage

First to answer will be the brainliest i need the answer asap

The doctor lands his tardis on a planet whose radius is 1.2x10^7m the acceleration due to gravity is 18m/s^2. what is the mass of the planet