Answer
D.Diffraction
Explanation
Diffraction is a property that is experienced by waves when they come across a barrier when they are in motion.
The ways tends to curve behind the barrier. This is called diffraction of waves.
Now, sound is a wave and it also experience diffraction. . So the brother will be able to hear the sound due to diffraction
Taking notes,because you can read back on what you learned
Answer:
14.8 m
Explanation:
S= ut + 
a
where u = initial velocity
S= (0 
)(2
) + (7.4
)(2
)
S= (7.4)(2)
S=14.8 m
Answer:
23.52 m/s
Explanation:
The following data were obtained from the question:
Time taken (t) to reach the maximum height = 2.4 s
Acceleration due to gravity (g) = 9.8 m/s²
Initial velocity (u) =..?
At the maximum height, the final velocity (v) is zero. Thus, we can obtain how fast the rock (i.e initial velocity)
was thrown as follow:
v = u – gt (since the rock is going against gravity)
0 = u – (9.8 × 2.4)
0 = u – 23.52
Collect like terms
0 + 23.52 = u
u = 23.52 m/s
Therefore, the rock was thrown at a velocity of 23.52 m/s.
Answer:
For the first situation, we first need to find the mass of the second train car.
In order to do that, we apply the conservation of the amount of movement:
and we have as a result:
m2 = 289.6875
For the second situation, also we will apply the conservation of the amount of movement:
and we have as a result:
V = 2.64 (it is moving to the right)
