<h2>
Answer: an underground lake</h2>
Explanation:
In general, sound (mechanical waves) travels faster in solids than in liquids, and faster in liquids than in gases. This is because <u>the speed of the mechanical waves is determined by a relationship between the elastic properties of the medium </u>in which they are propagated and the mass per unit volume of the medium (that is:<u>density</u>).
In other words: The speed of sound varies depending on the medium through which the sound waves travel.
So, if we are told the sound wave initially had a speed of 4,000 m/s and it suddenly decreases to 1,500 m/s, this means the sound waves passed from a solid medium to a liquid medium.
Hence, the correct option is: an underground lake.
Answer:
the average speed of the car is 170 mph.
Explanation:
Given;
initial speed, u = 70 mph
time of motion, t₁ = 3 hours
final speed, v = 20 mph
time of motion, t₂ = 2 hours
The average speed of the car is calculated as;
Therefore, the average speed of the car is 170 mph.
Answer:
Explanation:
The density of a material is given by:
(1)
Where:
is the mass of the cube
is the volume of the cube
Now, the volume of a cube is equal to the length of its edge to the power of 3:
(2)
If we know , the volume of this cube is:
(3)
Substituting (3) in (1):
(4)
This is the density of the cube
Answer:
2.9 m
Explanation:
First find the time it takes to reach the floor.
y = y₀ + v₀ t + ½ at²
(0 m) = (1.6 m) + (0 m/s) t + ½ (-9.8 m/s²) t²
t = 0.571 s
Next, find the distance it travels in that time.
x = x₀ + v₀ t + ½ at²
x = (0 m) + (5.0 m/s) (0.571 s) + ½ (0 m/s²) (0.571 s)²
x = 2.86 m
Rounded to two significant figures, the marble travels 2.9 meters in the x direction.
The required probability is 3/4.We have to compute the probability
P(Female |Junior) because we have to find the probability of the female student and the given condition is that the student is junior.
Determine the total number of juniors.Juniors=2+6=8
<h3>What is the probability?</h3>
Probability is the branch of mathematics concerning numerical descriptions of how likely an event is to occur, or how likely it is that a proposition is true. The probability of an event is a number between 0 and 1, where, roughly speaking, 0 indicates the impossibility of the event and 1 indicates certainty.
Since the number of females who are junior is 6, determine the required probability.
P(Female|Junior)=6/8=3/4
Therefore, the required probability is 3/4.
To learn more about the probability visit:
brainly.com/question/24756209
#SPJ1