Answer: 
Explanation:
Given
CD has a playing time of 
Initial angular speed of CD is 
Final angular speed of DC is 
Angular speed, when rpm is given


Final speed

Using equation of angular motion

Insert the values

Magnitude of angular acceleration is 
If two people are standing in different locations the length of the line is a measurement of distance
Answer:
Friction is the force resisting the relative motion of solid surfaces, fluid layers, and material elements sliding against each other. There are several types of friction: Dry friction is a force that opposes the relative lateral motion of two solid surfaces in contact.
Coefficient of friction, ratio of the frictional force resisting the motion of two surfaces in contact to the normal force pressing the two surfaces together. It is usually symbolized by the Greek letter mu (μ). Mathematically, μ = F/N, where F is the frictional force and N is the normal force.
Answer:
0.6 m/s
Explanation:
1.8 km = 1800 m
5 minutes= 300 s
Now,
Velocity = Displacement / time
= 1800/300
= 0.6 m /s
Answer:
15km/h East (15m/s East option)
Explanation:
Velocity = (change in) Distance/(change in) Time
The distance here is 60km, and the time is 4h, as given by the question. Therefore the velocity is 60km/4h = 15km/h.
To convert km/h to m/s, we just divide the value by 3.6, 15/3.6= 4.17m/s (2dp), which isn't actually an option here, so I'm assuming maybe a mistake in unit for the question?
'Velocity' is a vector quantity, meaning it has a size<em> </em>and a direction, as opposed to speed, a scalar quantity, which only has size. Therefore we need to add a direction for it to be velocity. The given direction here is east, so the velocity of the car is 15km/h East. (I would choose the 15m/s East as the question likely has a unit error and is closest.)
Hope this helped!