1. A 1.30 kg ball strikes a wall with a velocity of -10.5 m/s. The ball bounces off with a velocity of 6.50 m/s. If the ball is in contact with the wall for 0.0210 seconds, what is the force exerted on the ball by the wall?
O 1050 N
22.1 N
0 402 N
0 651 N
CAN SOMEONE PLS PLS ACTUALLY HELP ME

If the heat engine is a perfect carnot cycle engine, thenefficiency = (t2-t1)/t2   where t1=temperature of cold reservoir ( ° k) = 135            t2=temperature of hot reservoir ( ° k)   = 325thereforeefficiency = (t2-t1)/t2 = (325-135)/325 = 0.5846 = 58%  note: this is the theoretical maximum efficiency of a perfect heat engine.   real-life engines do not achieve this value.

Hi. i believe this is called a scientific  theory.cheers!

The cell reaction uses external supplies of a full and an oxidant, which are consumed and needs to be provided continuously. the cell will continue to provide electrical energy so long as there is a supply of fuel and oxidant.  hope this ! (:  

Answernewton's second law,says that when a contant force acts on a massive body, it causes it to accelerate