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:
(i) The angular speed of the small metal object is 25.133 rad/s
(ii) The linear speed of the small metal object is 7.54 m/s.
Explanation:
Given;
radius of the circular path, r = 30 cm = 0.3 m
number of revolutions, n = 20
time of motion, t = 5 s
(i) The angular speed of the small metal object is calculated as;

(ii) The linear speed of the small metal object is calculated as;

The visible spectrum ranges from 390 nm to 700 nm. the visible spectrum consist of the red ( 620 - 750 nm ) , orange ( 590 - 620 nm ) , yellow ( 570 - 590 nm ) , green ( 495 - 570 nm ) , blue ( 450 - 495 nm ) and violet ( 380 - 450 nm ) so the wave length 449 nm will produce a violet color