Because chemical changes result in different substances, they often cannot be undone. Some chemical changes can be reversed, but only by other chemical changes.
Answer:
356 000 J
Explanation:
Total Energy released
= Energy released when water cools to 0 + Energy released when water is converted to ice at 0
= mcT + ml
= (0.5)(4200)(90-0) + (0.5)(334 000)
= 189 000 J + 167 000 J
= <u>3</u><u>5</u><u>6</u><u> </u><u>0</u><u>0</u><u>0</u><u> </u><u>J</u>
Answer:
Copper's composition does not change as its shape changes, hence it is a physical feature.
Explanation:
(a) Amplitude=1.5 m
Amplitude is the maximum distance from the mean (zero disturbance) position.Here amplitude= 1.5 m
(b) wavelength= 2 m
Wavelength is the length of one complete wave or distance traveled by a wave in a time equal to Time Period. Here wavelength= 2 m
(c) Frequency=7.5 Hz
using equation for wave velocity V= f λ
15= f (2)
f=7.5 Hz
so frequency=7.5 Hz
(d) Time period= 0.133 s
Time period= T= 1/f
T= 1/7.5
T=0.133 s
so time period=0.133 s
