The question isn't clear enough, I think it ask us to calculate the linear speed of a point at the edge of the DVD.
Now let's imagine we're a point at the edge of the DVD, we're undergoing a circular motion. Each minute we will complete a circular track 7200 times, now we need to know the distance we travel each turn. The perimeter of the DVD, a circular object is:

Know recall that:

We now need to know how much distance is traveled during a minute or 60 seconds:

Finally we divide this result with t=60 seconds:


Where the distance units were named units as the length unit is not specified in this exercise.<span />
The correct option is A: the force exerted on the wall by the sledgehammer is - 1000 N
<h3>Newton's third law</h3>
Newton's third law of motion states that for every action or force, there is an equal but oppositely directed force.
<h3>Application of the newton's third law</h3>
Force with which the sledgehammer hits the wall = 1000 N
- From the Newton's third law, an equal but oppositely directed force is exerted on the sledgehammer by the wall.
Thus, the force exerted by the sledgehammer on the wall = -1000 N
- The negative sign indicates that the force acts in a direction opposite to that of the sledgehammer.
Thus, the correct option is A: the force exerted on the wall by the sledgehammer is - 1000 N
Learn more about Newton's third law and force at: brainly.com/question/13874955
Answer: 0.43kg
Explanation: a = 20.8m/s^2
F = 8.9N
m = ?
F = ma
8.9 = 20.8m
m = 8.9/20.8
= 0.43kg
Hope this helped..
Answer:
The charge on the wool after rubbing is - 10 C
Explanation:
Every uncharged body is electrically neutral, if the plastic rod acquires 10 Coulombs of charge after been rubbed with wool, then the wool will be left with an equal but opposite charge. This shows that the initial charge on the wool is 10 protons and 10 electrons and when the plastic acquires 10 C (10 protons), the wool will be left with excess 10 electrons.
Therefore, the charge on the wool after rubbing is - 10 C (negative 10 Coulombs).
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Below is the solution:
<span>T2cos(30) - T1cos(50) = 0
</span><span>T1sin(50) + T2sin(30) - (75 lbs.)*(accel. grav.) = 0
</span><span>T2cos(30) - T1cos(50) = 0 --> T1 = T2cos(30)/cos(50)
</span>
<span>T1sin(50) + T2sin(30) - (75 lbs.)*(accel. grav.) = 0
</span>(<span>T2cos(30)/cos(50))sin(50) + T2sin(30) - (75 lbs.)*(accel. grav.) = 0 --> Solve for T2
</span><span>T1 = -T1cos(50)i + T1sin(50)j
T2 = T2cos(30)i + T2sin(3)j
</span>
<span>(T2cos(30)/cos(50))sin(50) + T2sin(30) - (75 lbs.)*(accel. grav.) = 0 -->
T2[(cos(30)/cos(50))sin(50) + sin(30)] = 75*(grav) -->
T2 = 75*grav/ [(cos(30)/cos(50))sin(50) + sin(30)]
</span>
<span> T2 = 1566.49 </span>