Which best describes el niño
a .the water in the pacific ocean gets warmer than normal and cause fewer hurricanes to form
b . the water in the pacific ocean gets warmer than normal and the flow of the jet stream is disrupted

If the force applied to an object remains constant, is more power needed for the object to move faster ? explain

An athlete swings a ball, connected to the end of a chain, in a horizontal circle. the athlete is able to rotate the ball at the rate of 8.13 rev/s when the length of the chain is 0.600 m. when he increases the length to 0.900 m, he is able to rotate the ball only 6.04 rev/s. (a) which rate of rotation gives the greater speed for the ball? 6.04 rev/s 8.13 rev/s (b) what is the centripetal acceleration of the ball at 8.13 rev/s? m/s2 (c) what is the centripetal acceleration at 6.04 rev/s? m/s2

Ineed to answer this problem but i lack in knowledge, what should i study to answer this problem? i have never used derivatives in a physics problem so i'm not sure what's happening and i can't find videos explaining.