Answer:
c)While the amount of neutrinos passing through the Earth does not change much, there is something that changes to you at night. You stop moving and sleep for several hours.
Think of Neutrinos like rain. During the day you can avoid rain, and run from one dry spot to another(like from a car to a house). At night, however, your asleep, so the rain will hit you for eight hours(if your sleeping outside with no tent for some reason).
Answer:
115 m/s, 414 km/hr
Explanation:
There are two forces acting on a skydiver: gravity and air resistance (drag). At terminal velocity, the two forces are equal and opposite.
∑F = ma
D − mg = 0
D = mg
Drag force is defined as:
D = ½ ρ v² C A
where ρ is the fluid density,
v is the velocity,
C is the drag coefficient,
and A is the cross sectional surface area.
Substituting and solving for v:
½ ρ v² C A = mg
v² = 2mg / (ρCA)
v = √(2mg / (ρCA))
We're given values for m and A, and we know the value of g. We need to look up ρ and C.
Density of air depends on pressure and temperature (which vary with elevation), but we can estimate ρ ≈ 1.21 kg/m³.
For a skydiver falling headfirst, C ≈ 0.7.
Substituting all values:
v = √(2 × 80.0 kg × 9.8 m/s² / (1.21 kg/m³ × 0.7 × 0.140 m²))
v = 115 m/s
v = 115 m/s × (1 km / 1000 m) × (3600 s / hr)
v = 414 km/hr
Answer:
<em>The skydiver needs 0.71 seconds to reach 7 m/s</em>
Explanation:
<u>Free Fall Motion
</u>
When an object is dropped in free air (no friction) from a certain height h, it follows a free-fall motion, whose acceleration is due exclusively to gravity. The speed at a moment t when the object is dropped (from rest) is:
We need to find How long does the skydiver needs to reach 7 m/s. We solve for t
The skydiver needs 0.71 seconds to reach 7 m/s
