Answer:
The distance traveled by the skier is 5.309 km
Solution:
As per the question:
Mass of the skier, m = 64 kg
Coefficient of friction between the ski and the snow,
Mass of snow, M = 5.0 kg
Now,
To calculate the distance, 's' traveled by the skier, in order to melt 5.0 kg of snow:
We know that:
where
= coefficient of friction
N = Normal Reaction
N = mg
Thus
(1)
Also,
(2)
where
= Latent Heat of fusion
Thus from eqn (1) and (2):
s = 5.309 km
Answer:
C: Light travels from the Sun to the grass and is then reflected to your eyes.
Explanation:
Our eyes don't produce light but detect light (so answer A is not correct)
The grass doesn't produce light unless it is burning (discard answer B)
Answer C is the correct one.
The light we detect from the grass is not light bounced off the sky, it comes directly from the grass to your eyes (you are not looking at the sky when you see the grass) Discard answer D
Answer:
Explanation:
Given that,
Surface area A= 17m²
The speed at the top v" = 66m/s
Speed beneath is v' =40 m/s
The density of air p =1.29kg/m³
Weight of plane?
Assuming that,
the height difference between the top and bottom of the wind is negligible and we can ignore any change in gravitational potential energy of the fluid.
Using Bernoulli equation
P'+ ½pv'²+ pgh' = P'' + ½pv''² + pgh''
Where
P' is pressure at the bottom in N/m²
P" is pressure at the top in N/m²
v' is velocity at the bottom in m/s
v" is velocity at the top in m/s
Then, Bernoulli equation becomes
P'+ ½pv'² = P'' + ½pv''²
Rearranging
P' — P'' = ½pv"² —½pv'²
P'—P" = ½p ( v"² —v'²)
P'—P" = ½ × 1.29 × (66²-40²)
P'—P" = 1777.62 N/m²
Lift force can be found from
Pressure = force/Area
Force = ∆P ×A
Force = (P' —P")×A
Since we already have (P'—P")
Then, F=W = (P' —P")×A
W = 1777.62 × 17
W = 30,219.54 N
The weight of the plane is 30.22 KN
Answer:
Some of the effects of a dam on the environment includes;
1) Increase in the amount of the greenhouse gases
2) Removal of the natural wetland and ocean carbon sinks
3) Disruption of the sources of nutrients in the ecosystem
4) Destruction of habitats
5) Raising of the sea levels and waste waters
6) Displace villages and communities
7) Dams have a potential to create flood risk
8) Dams lead to increased water loss due to evaporation and transpiration
9) Dams causes earthquakes
Explanation:
Dams are a source of renewable energy and are a means to prevent floods, however, dams can also have detrimental impact on the climate and the environment.
Answer:
42KVA
Explanation:
Given data
High Voltage (HV)= 480V
Low Voltage (LV)= 277V
Fo find
Size of transformer=?
Solution
To find the size of transformer here we use the co-ratio.The Co-ratio is given as:
Co-Ratio= (HV - LV)/HV
where
HV is High Voltage
LV is Low Voltage
Now put the values we get
Co- Ratio=(480-277)/480=.42
So the size of transformer is 42KVA