Answer:
t₂ = t₁ / 5
Explanation:
Rotational kinematics using: ωf = ωi + αt
Starting from rest and speeding up:
ω₁ = 0 + αt₁ .. Eq1
Starting from ω₁ and slowing to a stop:
0 = ω₁ - 5αt₂
Substituting for ω₁ from Eq 1
0 = αt₁ - 5αt₂
5αt₂ = αt₁
5t₂ = t₁
t₂ = t₁ / 5
Answer:
c. (H-h/2) above the ground
Explanation:
The mirror must be at least half as tall as the alien, and its base must be located at half of the distance between the alien's eyes and the ground (assuming that the alien doesn't float or levitate).
This question is about the Law of Reflection which states that the angle of reflection = angle of incidence.
I attached an image that can help you understand the concept, although the alien is not included.
20N..........................
Answer:
122.5 kW
Explanation:
m = mass of the loaded elevator = 2.50 x 10³ kg = 2500 kg
t = time taken to raise the elevator = 10.0 s
h = height gained by the elevator = 50.0 m
g = acceleration due to gravity = 9.8 m/s²
Power spent is given as
P =
Inserting the values
P =
P = 122500 Watt
P = 122.5 kW (Since 1 kW = 1000 W)