Answer:
12.495m/s
Explanation:
Horizontal displacement is the range of the projectile motion.
The range is expressed as;
R = 2U/g
U is the speed at which the rock is thrown (initial speed)
g is the acceleration due to gravity.
Given
R = 255cm = 2.55m
g = 9.8m/s²
Required
Speed U
Substitute the given parameters into the formula as shown;
2.55 = 2U/9.8
Cross multiply
2U = 2.55×9.8
2U = 24.99
U = 24.99/2
U = 12.495m/s
Hence the speed that you thew the rock is 12.495m/s
Explanation:
Loudness of sound is a measure of response of sound to our ear. Loudness of sound is not simply the energy reaching the human ear, but it also tells about the sensitivity of human ear detecting this energy. Loudness of sound is measured in decibel (dB). As energy reaching the ear depends on square of amplitude, loudness of sound depends on various factors namely,
(i) Amplitude of sound waves
(ii) Sensitivity of ear
(iii) Distance from the source of the sound and the listener.
Answer:
Water and Oxides such as iron oxide or rust
Explanation:
