Answer:
v = 8.09 m/s
Explanation:
For this exercise we use that the work done by the friction force plus the potential energy equals the change in the body's energy.
Let's calculate the energy
starting point. Higher
Em₀ = U = m gh
final point. To go down the slope
Em_f = K = ½ m v²
The work of the friction force is
W = fr L cos 180
to find the friction force let's use Newton's second law
Axis y
N - W_y = 0
N = W_y
X axis
Wₓ - fr = ma
let's use trigonometry
sin θ = y / L
sin θ = 11/110 = 0.1
θ = sin⁻¹ 0.1
θ = 5.74º
sin 5.74 = Wₓ / W
cos 5.74 = W_y / W
Wₓ = W sin 5.74
W_y = W cos 5.74
the formula for the friction force is
fr = μ N
fr = μ W cos θ
Work is friction force is
W_fr = - μ W L cos θ
Let's use the relationship of work with energy
W + ΔU = ΔK
-μ mg L cos 5.74 + (mgh - 0) = 0 - ½ m v²
v² = - 2 μ g L cos 5.74 +2 (gh)
v² = 2gh - 2 μ gL cos 5.74
let's calculate
v² = 2 9.8 11 - 2 0.07 9.8 110 cos 5.74
v² = 215.6 -150.16
v = √65.44
v = 8.09 m/s
Answer:
441 [N].
Explanation:
Weight=mass*g, where mass=45; g=9,8.
Weight=45*9.8=441 [N].
Answer:
A and B
Explanation:
The relation between frequency and wavelength is shown below as:

c is the speed of light having value 
Thus, the product of the wavelength and the frequency is constant and equal to 
<u>Option A is correct.</u>
Given, Frequency = 
Thus, Wavelength is:



Also, 1 m =
Å
So,
<u>Wavelength = 3.0 Å</u>
<u>Option B is correct.</u>
As stated above, the speed of electromagnetic radiation is constant. Hence, each radiation of the spectrum travels with same speed.
<u>Option C is incorrect.</u>
Answer:
Water is not able to be used as a thermometer liquid because of its higher freezing point and lower boiling point than the other liquids in general. If water is used in a thermometer, it will start phase variation at 0∘C and 100∘C. This will not help in measuring temperature, beyond this range.
Explanation:
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Answer:
4.2 J
Explanation:
Specific heat capacity: This is defined as the amount of a heat required to rise a unit mass of a substance through a temperature of 1 K
From specific heat capacity,
Q = cmΔt.............................. Equation 1
Where Q = amount of energy absorbed or lost, c = specific heat capacity of water, m = mass of water, Δt = Temperature rise.
Given: m = 1 g = 0.001 kg, Δt = 1 °C
Constant : c = 4200 J/kg.°C
Substitute into equation 1
Q = 0.001×4200(1)
Q = 4.2 J.
Hence the energy absorbed or lost = 4.2 J