Answer:
D. All of the above
Explanation:
Global warming may cause all of the given choices.
Global warming is the rise in surface temperature. This is due to the trapping of heat within the earth surface.
It is as a result of huge amount of greenhouse gases within our atmosphere. They typically permit short wave radiations to escape and they do not allow short wave radiation to pass through. This in turn produces heat.
- The heat can melt polar ices and glaciers.
- This in turn will cause sea levels to rise.
- Also, the ocean temperature will generally increase due to this.
The work that you do on the lever will be the same as the work done by the lever on the rock. This aligns with the Law of the Conservation of Energy which states that energy can not be created nor destroyed. Since work can be calculated as force applied over a distance, you will apply a smaller force but your distance will be longer. The lever will apply a greater force over a shorter distance in proportion to yours. Therefore, the same amount of work is done on both sides of the lever.
Answer:
5.03 m/s
Explanation:
Give
Speed = v = 24m/s
Wavelength = λ = 30cm = 0.3m
Amplitude = A = 1.0cm = 0.01m
The velocity of a point in Simple Harmonic Motion
at any time t is given by the following formula
v = ωA cos ωt
The value is the Maximum when cosωt.
The maximum value of cosωt. is 1.
Hence the maximum velocity is ωA
Velocity of the wave v=n λ
n = v/ λ = 24 /0.3 = 80
ω = 2πn = 2π*80 = 502.86 rad/s
Maximum velocity of the particle is
ωA = 502.86 * 0.01 = 5.03m/s
Answer:
y = 2.74 m
Explanation:
The linear thermal expansion processes are described by the expression
ΔL = α L ΔT
Where α the thermal dilation constant for concrete is 12 10⁻⁶ºC⁻¹, ΔL is the length variation and ΔT the temperature variation in this case 20ªc
If the bridge is 250 m long and is covered by two sections each of them must be L = 125 m, let's calculate the variation in length
ΔL = 12 10⁻⁶ 125 20
ΔL = 3.0 10⁻² m
Let's use trigonometry to find the height
The hypotenuse Lf = 125 + 0.03 = 125.03 m
Adjacent leg L₀ = 125 m
cos θ = L₀ / Lf
θ = cos⁻¹ (L₀ / Lf)
θ = cos⁻¹ (125 / 125.03)
θ = 1,255º
We calculate the height
tan 1,255 = y / x
y = x tan 1,255
y = 125 tan 1,255
y = 2.74 m