Answer:
75degree don't forget wind and gravity force pulling down
Answer:0.69
Explanation:
Coefficient of kinetic friction=f/R=61.8/90=0.69
The operating coefficient or performance coefficient of a heat pump is the ratio between the heating or cooling provided and the electricity consumed. The higher coefficients are equivalent to lower operating costs. The coefficient can be greater than 1, because it is a percentage of the output: losses, other than the thermal efficiency ratio: input energy. Mathematically can be written as,


Replacing,


Therefore the heat is 3.822kJ
The velocity increased from 4 m/s to 22 m/s in 3 seconds. 18 m/s in 3 seconds so the average acceleration is change in velocity divided by time. 18 m/s divided by 3 seconds = 6 m/s^2
The answer would be letter choice B