Answer:
a) P = 807.85 N, b) P = 392.15 N, c) P = 444.12 N
Explanation:
For this exercise, let's use Newton's second law, let's set a reference frame with the x-axis parallel to the plane and the direction rising as positive, and the y-axis perpendicular to the plane.
Let's use trigonometry to break down the weight
sin θ = Wₓ / W
cos θ = W_y / W
Wₓ = W sin θ
W_y = W cos θ
Wₓ = 1200 sin 30 = 600 N
W_y = 1200 cos 30 = 1039.23 N
Y axis
N- W_y = 0
N = W_y = 1039.23 N
Remember that the friction force always opposes the movement
a) in this case, the system will begin to move upwards, which is why friction is static
P -Wₓ -fr = 0
P = Wₓ + fr
as the system is moving the friction coefficient is dynamic
fr = μ N
fr = 0.20 1039.23
fr = 207.85 N
we substitute
P = 600+ 207.85
P = 807.85 N
b) to avoid downward movement implies that the system is stopped, therefore the friction coefficient is static
P + fr -Wx = 0
fr = μ N
fr = 0.20 1039.23
fr = 207.85 N
we substitute
P = Wₓ -fr
P = 600 - 207,846
P = 392.15 N
c) as the movement is continuous, the friction coefficient is dynamic
P - Wₓ + fr = 0
P = Wₓ - fr
fr = 0.15 1039.23
fr = 155.88 N
P = 600 - 155.88
P = 444.12 N
Answer:
a) 5.5×10^17 Hz
b) visible light
Explanation:
Since the wavelength of the electromagnetic radiation must be about the size of the about itself, this implies that;
λ= 5.5 × 10^-10 m
Since;
c= λ f and c= 3×10^8 ms-1
f= c/λ
f= 3×10^8/5.5 × 10^-10
f= 5.5×10^17 Hz
The electromagnetic wave is visible light
Answer:Frequency = 3.525 Hertz
Explanation:In static equilibrium, kd =mg
Where k= effective spring constant of the spring.
mg= The weight of the car.
d= static deflection.
Therefore, w =SQRTg/d
w = SQRT 9.81/0.02
w= 22.15 rad/sec
Converting to Hertz unit for frequency
1 rad/s = 0.1591
22.15rad/s=?
22.15 × 0.1591= 3.525 hertz
Answer: water freezes inside a rock, causing it to break
Weathering is a natural process in which the rocks break into pieces or sediments by the action of wind, water and chemical agents. Frost wedging is a physical weathering process. It occurs in an area where temperature fluctuations occurs due to change in the climatic conditions. This occurs due to rapid heating and cooling. The rocks lying in a cold environment, the water residing in the rocks gets freezed. The water in ice form that is solid form acquire more space than in liquid form, therefore, the developed ice will affect the physical structure of the rock. The formation of ice results in the development of break or crack in the rock typically in the shape of a wedge and thus the phenomena is called as frost wedging.
Hence, frost wedging happens when water freezes inside a rock, causing it to break.
Answer:
I. 6 cells .
II. Series connection.
Explanation:
I. Determination of the number of cells needed.
From the question given above,
Total voltage (V) = 9 V
1.5 V = 1 cell
Number of cells needed =?
The number of cells needed to make the 9V battery can be obtained as follow:
1.5 V = 1 cell
Therefore,
9 V = 9 V × 1 cell / 1.5 V
9 V = 6 cells
Thus, 6 cells of 1.5 V each is needed
II. Determination of the connection line
Total voltage (Vₜ) = 9 V
Cell 1 (V₁) = 1.5 V
Cell 2 (V₂) = 1.5 V
Cell 3 (V₃) = 1.5 V
Cell 4 (V₄) = 1.5 V
Cell 5 (V₅) = 1.5 V
Cell 6(V₆ ) = 1.5 V
For parrall connection:
Vₜ = V₁ = V₂ = V₃ = V₄ = V₅ = V₆
9 V = 1.5 V =... = 1.5 V
For series connection:
Vₜ = V₁ + V₂ + V₃ + V₄ + V₅ + V₆
9 = 1.5 + 1.5 + 1.5 + 1.5 + 1.5 + 1.5
9 V = 9 V
From the illustration above, we can see that series connection of each cells will give a total volt of 9 V unlike the parallel connection which resulted to 1.5 V.
Therfore, the cells should be arranged in series connection
