Answer:
(a) Time t = 16.46 sec
(b) Time t =13.466 sec
(c) Deceleration = 
Explanation:
(a) As the train starts from rest its initial velocity u = 0 m/sec
Acceleration 
Final speed v = 80 km/hr
From first equation of motion v =u+at
So 
(b) Now initial speed u = 22.22 m/sec
As finally train comes to rest so final speed v=0 m/sec
Deceleration 
So 
(c) We have given that initial velocity = 80 km/hr = 22.22 m/sec
Final velocity v = 0 m/sec
Time t = 8.30 sec
So acceleration is given by
As acceleration is negative so it is a deceleration
Neither technician is correct.
Please don't touch my car.
Explanation:
d = Diameter of wheel = 27 cm
r = Radius = 
m = Mass of wheel = 800 g
= Initial angular velocity = 
Equation of rotational motion
Moment of inertia is given by
Torque is given by
The torque the friction exerts is -0.0037406448 Nm
For more information on torque and moment of inertia refer
brainly.com/question/13936874
brainly.com/question/3406242
Answer:
Elliptical galaxies
Explanation:
Edwin Hubble classified galaxies into three categories
Elliptical
Spiral
Lenticular
The elliptical galaxies have an elipsoidal shape roughly. They have stars which are old and the primary light source of the galaxy. The formation of new stars is very limited. This increases the brightness of the galaxy. The mass of the stars are low. So, far the percentage elliptical galaxies is low compared to other galaxies.
They correspond due to the fact that certain elements are grouped together based on the number of valence electrons on the outer shell of their electron configuration.
For instance, sulfur (S) has 6 electrons in the outer shell, as it is in the 6th group EXCLUDING transition metals (note, never take these into account, as their charge is always +2; a cation)
