Could be that the speed of sound is 330m/s
Speed = m/s
Velocity can be negative, but speed cannot.
70 - 68 = 2
2/14 = 0.143 m/s
I think its c sorry if I’m wrong
Answer:
The wavelength will be 4 cm, frequency will be 4.66 Hz and wave speed is 18.6 cm/sec
Explanation:
Given:
No. of crest = 13
No. of trough = 15
Time = 3 seconds
Hence, 1 crest or 1 trough = 
therefore,
13 C + 15 T = 
=
Time given 3 seconds
= 

2 cm distance is travelled is time period

Again wave will travel in 1 T = 4 cm
wave speed v =
= 
= 18.6 cm/s
Radars are frequently used to identify distance and speed, such as how far away an object is or how fast it is moving. <span>The </span>radar<span> device can then use the change in frequency to </span>determine the speed<span> at which the </span>car<span> is moving. In laser-</span>speed<span> guns, waves of light are </span>used<span> in place of radio waves.</span>