A. Coal is used to primarily to produce and generate electricity and it is responsible for 39 percent of the power supply for the united states.
Answer:
Explanation:
The direction of force will be in upward direction making an angle of θ with the vertical .
Reaction force R = mg - F cosθ
Friction force = μR
= .36 (mg - F cosθ )
Horizontal component of applied force
= F sinθ
For equilibrium
F sinθ = .36 (mg - F cosθ)
F sinθ + .36 F cosθ =.36 mg
F (sinθ + .36 cosθ) = .36 mg
F R( cosδsinθ +sinδ cosθ) = .36 mg ( Rcosδ = 1 . Rsinδ= .36 )
F R sin( θ+δ ) = . 36 mg
F = .36 mg / Rsin( θ+δ )
For minimum F , sin( θ+δ ) should be maximum
sin( θ+ δ ) = sin 90
θ+ δ = 90
Rsinδ / Rcosδ = .36
δ = 20⁰
θ = 70⁰ Ans
Answer: question 1 , would be one question 2 , would be 1 joule and number three would be number one and number four would be , power and last one would be, number two
Explanation: sorry if its wrong
Answer:
Explanation:
Given
-- initial velocity
--- height
Required
Determine the time to hit the ground
This will be solved using the following motion equation.
Where
So, we have:
Subtract 30.2 from both sides
Solve using quadratic formula:
Where
Split the expression
or 
or 
Time can't be negative; So, we have:
Hence, the time to hit the ground is 1.82 seconds
