Potential energy is energy stored in an object. kinetic energy is energy of motion
All of the following
involve waves of electromagnetic energy except the rumble of thunder during a storm.
Electromagnetic waves<span> <span>are
used to transmit long/short/FM wavelength radio </span>waves, and TV/telephone/wireless signals or energies. They are
also responsible for transmiting energy in the form of microwaves, infrared radiation<span> (IR), visible light (VIS),
ultraviolet light (UV), X-rays, and gamma rays.</span></span>
The correct answer between all
the choices given is the second choice or letter B. I am hoping that this
answer has satisfied your query and it will be able to help you in your
endeavor, and if you would like, feel free to ask another question.
Answer:
V = 6.3 m/s
Explanation:
Given:
m₁ = 2 kg
m₂ = 18 kg
m₃ = 9 kg
V₁ = 10 m/s
V₂ = 8 m/s
V₃ = 2 m/s
__________
V - ?
Let us write the momentum conservation law for an inelastic impact:
m₁·V₁ + m₂·V₂ + m₃·V₃ = (m₁ +m₂ + m₃) ·V
Cart speed after interaction:
V = ( m₁·V₁ + m₂·V₂ + m₃·V₃ ) / (m₁ +m₂ + m₃)
V = (2·10 + 18·8 + 9·2) / ( 2 + 18 + 9) = 182 / 29 ≈ 6.3 m/s
Answer: 3.4s
Explanation:
There are three stages in the motion of the ball, so you have to calculate the times for every stage.
1) Ball dropping from 9.5m: free fall
d = Vo + gt² / 2
Vo = 0 ⇒ d = gt² / 2 ⇒ t² = 2d / g = 2 × 9.5 m / 9.81 m/s² = 1.94 s²
⇒ t = √ (1.94 s²) = 1.39s
2) Ball rising 5.7m (vertical rise)
i) Determine the initial speed:
Vf² = Vo² - 2gd
Vf² = 0 ⇒ Vo² = 2gd = 2 × 9.81 m/s² × 5.7m = 111.8 m²/s²
⇒ Vo = 10.6 m/s
ii) time rising
Vf = Vo - gt
Vf = 0 ⇒ Vo = gt ⇒
t = Vo / g = 10.6 m/s / 9.81 m/s² = 1.08 s
3) Ball dropping from 5.7 m to 1.20m above the pavement (free fall)
i) d = 5.7m - 1.20m = 4.5m
ii) d = gt² / 2 ⇒ t² = 2d / g = 2 × 4.5 m / 9.81 m/s² = 0.92 s²
⇒ t = √ (0.92 s²) = 0.96s
4) Total time
t = 1.39s + 1.08s + 0.96s = 3.43s ≈ 3.4s
