The echo is heard 2.80 s later, this means this is the time the sound takes to travel to the reflecting object and then back to us. So, during this time, the sound wave has covered the distance L between us and the object twice:
The speed of the sound wave is:
, and since it is moving by uniform motion, we can find the distance covered by the wave using
And we said this corresponds to twice the distance between us and the reflecting object, so:
so, the object is 480 meters away.
a) The velocity of the boat relative to the shore is 3.40 m/s and b) The position of the boat relative to its point of origin after 3s is 10.20m.
Here it is given that the speed of the boat (x) = 2.20m/s
The speed of the stream current (y) = 1.20m/s
a) We have to find the velocity of the boat relative to the shore.
The speed of the boat = x + y
= 2.20 + 1.20
= 3.40m/s
b) Now we have to find the position of the boat after 3s
The formula for speed:
Speed = Distance/ Time
distance = speed × time
speed = 3.40m/s
Time = 3s
distance = 3.40 × 3
= 10.20 m
Therefore we get a) speed as 3.40m/s and b) distance as 10.20m.
To know more about the boat and stream refer to the link given below:
brainly.com/question/382952
#SPJ4
The correct answer to the question is : Transverse wave.
EXPLANATION :
Before going to answer this question, first we have to understand the longitudinal and transverse wave.
LONGITUDINAL WAVE : A longitudinal wave is a mechanical wave in which the direction of vibration of particles is parallel to the direction of wave propagation. It moves in the form of compression and rarefaction.
For instance, sound wave.
TRANSVERSE WAVE : A transverse wave is a mechanical wave in which the direction of vibration of particles is perpendicular to the direction of wave propagation. It moves in the form of crests and troughs.
For instance, the wave created in a pond when a stone is dropped into it.
Hence, the correct answer of this question is transverse wave.
Just find the density of every metal and select the one with a density of 2.71 g/cm³ . This is:
Metal 1
ρ = m/V
ρ = 22.1 g / 3 cm³
ρ = 7.367 g / cm³
Metal 2
ρ = m/V
ρ = 42 g / 4 cm³
ρ = 10.5 g / cm³
Metal 3
ρ = m/V
ρ = 9.32 g / 5 cm³
ρ = 1.864 g / cm³
Metal 4
ρ = m/V
ρ = 8.13 g / 3 cm³
ρ = 2.71 g / cm³
<h2>R / Metal 4 was selected.</h2>
