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.
Power is the rate at which energy is used in a circuit.
Answer:
1. D
2. D
3. A
The reason why your body goes right and the car car goes left is because your body tries to stay where it was, which is on the right. Your upper body doesn't feel a force and because of that continues in the same direction. Your lower half is pulled out from under you by seat friction to the left, leaving you leaning to the right.
Answer:
0.5 m/s².
Explanation:
From the question given above, the following data were obtained:
Initial velocity (u) = 0 m/s
Final velocity (v) = 10 m/s
Time (t) = 20 s
Acceleration (a) =?
Acceleration can simply be defined as the rate of change of velocity with time. Mathematically, it is expressed as:
a = (v – u) / t
Where:
a is the acceleration.
v is the final velocity.
u is the initial velocity.
t is the time.
With the above formula, we can obtain the acceleration of the car as follow:
Initial velocity (u) = 0 m/s
Final velocity (v) = 10 m/s
Time (t) = 20 s
Acceleration (a) =?
a = (v – u) / t
a = (10 – 0) / 20
a = 10/20
a = 0.5 m/s²
Therefore, the acceleration of the car is 0.5 m/s².
C.
Because it’s falling it has acceleration in the y direction. If you have acceleration, you usually also have velocity, and since kinetic energy is KE= Mv^2 you know you have it. It also has potential energy because it has some height to it, and PE= Mgh.
