Solution :
Given
Diameter of the roulette ball = 30 cm
The speed ball spun at the beginning = 150 rpm
The speed of the ball during a period of 5 seconds = 60 rpm
Therefore, change of speed in 5 seconds = 150 - 60
= 90 rpm
Therefore,
90 revolutions in 1 minute
or In 1 minute the ball revolves 90 times
i.e. 1 min = 90 rev
60 sec = 90 rev
1 sec = 90/ 60 rec
5 sec =
= 75 rev
Therefore, the ball made 75 revolutions during the 5 seconds.
This law states that, despite chemical reactions or physical transformations, mass is conserved — that is, it cannot be created or destroyed — within an isolated system
Whenever these are an alarming due to a foreign antigen, the Helper T cells, Memory T cells, and Cytotoxic T cells are being produced. Helper T cells to recognize the specific foreign antigen that is entering the body, Memory T cells to remember the specific foreign antigen that is attacking, and Cytotoxic T cells that are for the destruction of the foreign cells and produce cytokines to attract macrophages
Answer:
Star A
Explanation:
μ = proper motion = 1 arcsecond per year
r = 20 light-years = Distance
Transverse velocity
V = 1.45 × μ × r
⇒ V = 1.45 × 1 × 20
⇒ V = 29 km/sec
When r = 10 light-years
V = 1.45 × 1 × 10
⇒ V = 14.5 km/sec
∴ Star A which is 20 light-years from Earth is moving faster compared to Star B which is 10 light-years from Earth.