Answer:The frequency of the echo is slightly decreased
Explanation:
Given
speed of boat 
cliff is
away
when boat is still , suppose t is the time taken by the echo to reach observer on the boat
But as soon as boat starts moving the distance between cliff and boat decreasing and time for echo to reach observer also decreases
and we know 
therefore frequency of the echo slightly decreased.
Do u know Chinese ?if yes I can explain to u easily
Answer:
33.33 m/sec
Explanation:
A baseball travels 200 metes in 6 seconds,
what is the baseball’s velocity?
use the formula: velocity = distance over time
where (d) distance = 200 m
and (t) time = 6 sec.
plugin values into the formula:
v = d / t
= 200 m / 6 sec
= 33.33 m/sec.
therefore, the baseball's velocity is 33.33 m/sec
A. Diagram A
B. Diagram C & D
C. Diagram B
D. Diagram C & D
E. Diagram B
F. Diagram C & D
These are simplified representations of an object's body and the force vectors acting on it. Some of the main forces that are involve are normal force, friction, push or pull and gravity.
Answer:
when the ground is very hot and the air is cool.
Explanation:
The hot earth warms a layer of air right above the ground. Light is refracted as it passes through the cool air and onto the hot air sheet (bent). A coating of very warm air near the earth bends the light from the sky almost into a U-shaped bend.