All of the following examples involve chemical energy except: a. working muscles using food b. burning a candle c. lightng a match .d. coasting downhill on a bike

explanation:

a fuel engine ( known as a gasoline engine in american english )is an internal combustion engine with spark ignition, designed to run on petrol (gasoline) and similar volatile fuels.

acceleration = (change in speed) / (time for the change)

change in speed = (20-120)= -100 m/s.

1.5 min = 90 sec

acceleration = -100/90 = -1.11 m/s^2.

we don't care about the 150kg or the 2,500 meters. they don't make any difference.

read more on -

grav potential energy

find the sum of the two horizontal vectors and the sum of the two vertical vectors

isoceles right angled triangle