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.
Answer:
you count the squares or messure it
Explanation:
you can raw equal squares about 1 cm wide if possible all equal and count the squares eg theres 10 squares (small hand) so that would be 10cm squared
Answer:
a physical change
Explanation:
after the water turns to ice, it will melt and became water again making which means it's reversible this being. a physical change
Answer:
f = 6.37 Hz, T = 0.157 s
Explanation:
The expression you have is
y = 5 sin (3x - 40t)
this is the equation of a traveling wave, the general form of the expression is
y = A sin (kx - wt)
where A is the amplitude of the motion, k the wave vector and w the angular velocity
Angle velocity and frequency are related
w = 2π f
f = w / 2π
from the equation w = 40 rad / s
f = 40 / 2π
f = 6.37 Hz
frequency and period are related
f = 1 / T
T = 1 / f
T = 1 / 6.37
T = 0.157 s
