Answer:
f = 692 N
Explanation:
given data:
f =800N
a =1.2 m s^{2}
m= 90 kg
from newton's second law
net force 
therefore we have from above equation
ma =F - f
putting all value to get force of friction
1.2*90 = 800 - f
f = 692 N
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
Answer: That's air resistance.
Explanation: Well, air resistance is an upward force exerted on falling objects.
( I hope this helped <3 )
This equation is one of the most useful in classical physics. It is a concise statement of Isaac Newton's<span> Second Law of Motion, holding both the proportions and vectors of the Second Law. It translates as: The net force on an object is </span>equal<span> to the </span>mass<span>of the object multiplied by the </span>acceleration<span> of the object.</span>