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:
d)infrared waves
Explanation:
A remote control uses light waves just beyond the visible spectrum of light—infrared light waves—to change channels on your TV. This region of the spectrum is divided into near-, mid-, and far-infrared.
Answer:
Acceleration of the plane, a = 5.4 g
Explanation:
It is given that,
Speed of the jet plane, v = 1890 km/h = 525 m/s
Radius of the arc, r = 5.20 km = 5200 m
The plane is moving in the circular path, the centripetal acceleration will act on it. It is given by :



We know that, the value of g is, 


So, the acceleration of the plane is 5.4 g. Hence, this is the required solution.
Answer:
Explanation:
Given: Density of blood = 1.03 × 10³ Kg/m³, Height = 1.93 m g = 9.8 m/s²
pressure at the brain is equal to atmospheric pressure. = Hydro-static
pressure(ρ₀)
∴ pressure of the foot = pressure of the brain(ρ₀) + ( density of blood × acceleration due to gravity × height)(ρgh)
Hydro-static pressure = pressure at the feet- pressure at the brain(ρ₀)
Hydro-static pressure (Δp) = (ρgh + ρ₀) - ρ₀ = ρgh
Hydro-static pressure = 1.03 × 10³ × 9.8 × 1.93 = 1.948 × 10⁴ Pa
∴ Hydro-static pressure ≈ 1.95 × 10⁴ Pa