Answer:
Number of revolutions = Δθ = 60.63 revs
Explanation:
The angular acceleration of the washer is given by
α = (ωf - ωi)/Δt
Where ωf is the initial angular speed, ωi is the final angular speed and Δt is the interval of time during this acceleration.
α = (4.7 - 0)/8.3
α = 0.56 rev/s²
As we know from the equation of kinematics,
2αΔθ = ωf² - ωi²
Where Δθ is the change in angular displacement of the washer.
Δθ = (ωf² - ωi²)/2α
Δθ = (4.7² - 0²)/2*0.56
Δθ = 19.72 revs
Now the tub decelerates and comes to a stop in 17.5 s
α = (ωf - ωi)/Δt
α = (-4.7 - 0)/17.5
α = -0.27 rev/s²
the corresponding change in angular displacement of the washer is
Δθ = (ωf² - ωi²)/2α
Δθ = (0² - 4.7²)/2*-0.27
Δθ = 40.91 revs
Therefore, the total number of revolutions undergone by the tub during this entire time interval is
Δθ = 19.72 + 40.91
Δθ = 60.63 revs
Answer:
Explanation:
You need to look at this in 3 separate stages, and then sum thedistance from each stage:
Stage 1)
a=2
t=20
=0
We also need to find the final velocity
Stage 2)
a=0
v=40
t=20
Stage 3)
a=-3
=40
=0
So the total distance is
Answer:
14.3kg
Explanation:
Given parameters:
Quantity of heat = 149000J
Change in temperature = 5.23°C
specific heat of the ice = 2000J/kg°C
Unknown:
Mass of the ice in the bag = ?
Solution:
The heat capacity of a substance is given as:
H = m c Ф
H is the heat capacity
m is the mass
c is the specific heat
Ф is the temperature change;
since m is the unknown, we make it the subject of the expression;
m = H/ mФ
m = = 14.3kg
Answer:
1- Surface water
2- Groundwater
3- Lake
4- River
5- Watershed/Catchment basin
6- Wetland
Explanation:
- Surface water refers to all the water bodies that are present on the surface of the earth. This includes rivers, streams, ponds, lakes.
- Groundwater refers to the subsurface flow of water. When precipitation occurs, the water percolates downward through the rocks in the region where the rocks are porous and permeable, and this water then becomes groundwater.
- A lake is usually defined as a large water body that is comprised of nutrient minerals and has extensive areas of open water. The depth of the lakes from one place to another and some are so deep that sunlight cannot penetrate into the deeper zone and the plants cannot carry out the process of photosynthesis.
- A river is defined as a water body that flows from a region of higher elevation to the region of lower elevation and it flows across the land surface and configures the landscape.
- Catchment basin is usually defined as a large area in which the precipitation occurs and the waters are accumulated and flow downward and mix up with the river channel and streams.
- Wetlands are usually defined as an ecosystem that is comprised of shallow standing water, and a sufficient amount of vegetation.
Aristotle believed that the Earth was orbited by the sun, moon, and the other planets which he referred to as Celestial Bodys