Answer:
The energy that the truck lose to air resistance per hour is 87.47MJ
Explanation:
To solve this exercise it is necessary to compile the concepts of kinetic energy because of the drag force given in aerodynamic bodies. According to the theory we know that the drag force is defined by

Our values are:




Replacing,


We need calculate now the energy lost through a time T, then,

But we know that d is equal to

Where
v is the velocity and t the time. However the time is given in seconds but for this problem we need the time in hours, so,

(per hour)
Therefore the energy that the truck lose to air resistance per hour is 87.47MJ
Answer:
m=image distance÷object distance
Answer:
The angle of bend = 20°
Explanation:
Since the question describes that the angle marking is similar to the metre stick marking.
The length of the object when it begins at 0 meters on the meter rule
= 1.2 m
The length of the meter stick when it begins at 0.2 m on the meter rule
= 1.0 m
The difference in length of the object based on the markings
= 1.2 - 1.0 = 0.2 m
If the green marking is on 223°, i.e. θ₂ = 223°
and the straight marking is on 253°, i.e. θ₁ = 253°
The angle of bend = θ₁ - θ₂
The angle of bend = 253° - 223°
The angle of bend = 20°