Answer:
(A) 60 J
Explanation:
At state 1
KE₁=100 J
At state 2
KE₂ = 0
U₂=80 J
Given that surface is rough so friction force will act in opposite to the direction of motion
Lets take work done by friction = Wfr
From work power energy
Work done by all forces = Change in kinetic energy
Wfr + U₂=ΔKE
Wfr+80 = 100
Wfr= 20 J
Now when book slides from top position then
Wfr+ U = KEf - KEi
-20 + 80 = KEf-0
KEf= 60 J
(A) 60 J
<span>Final Velocity = Vf = 0 m/s --------------> (Vf = 0 because ball's speed at its max height is 0)
Initial Velocity = Vi = ?
Total time (upward & downward) = 8.0 seconds
* Time upward = 4 seconds & ................( As time for ball upward & downward is equal )
* Time downward = 4 seconds..
Gravitational Acceleration = g = -9.8 m/s²
Use Equation;
Vf = Vi - gt
0 = Vi - 9.8 * 4
0 = Vi - 39.2
39.2 = Vi
=> Vi = Initial Velocity = 39.2 m/s</span>
Answer:
all of the above
Explanation:
- a build up of electric charge
- the force and motion of electrically charged particles
- an electric current
are three different ways to describe electricity.
So the answer is all of the above.
Answer: Economic growth is the main channel. Globalization can affect poverty. when countries open up to trade, they tend to grow faster and living standards do tend to increase.
Explanation: I hope this helps :)
Answer:
Not quite
Explanation:
The frequency of a wave is inversely proportional to its wavelength. That means that waves with a high frequency have a short wavelength, while waves with a low frequency have a longer wavelength
What determines the strength of a wave?
Wave height is affected by wind speed, wind duration (or how long the wind blows), and fetch, which is the distance over water that the wind blows in a single direction. If wind speed is slow, only small waves result, regardless of wind duration or fetch.
So,
As Wavelength increases, The energy of the wave spreads and it decreases
