<h2>Hello!</h2>
The answer is: B. Kinetic energy
<h2>
Why?</h2>
Since the ball is falling, speed increases because the gravity acceleration is acting. When speed increases, the kinetic energy increases too, so the ball is gaining kinetic energy.
The gravity acceleration is equal to
, it means that when falling, the ball will increase it's speed 9.81m every second.
We can calculate the kinetic energy by using the following formula:

Where:

Have a nice day!
<h2 />
Fish swimming forward in the water, the water gets pushed backward because the fish moving forward is forcing the water to move backward, the motion forward and backward are the same, they are opposite and equal.
Answer:
Explanation:
a ) starting from rest , so u = o and initial kinetic energy = 0 .
Let mass of the skier = m
Kinetic energy gained = potential energy lost
= mgh = mg l sinθ
= m x 9.8 x 70 x sin 30
= 343 m
Total kinetic energy at the base = 343 m + 0 = 343 m .
b )
In this case initial kinetic energy = 1/2 m v²
= .5 x m x 2.5²
= 3.125 m
Total kinetic energy at the base
= 3.125 m + 343 m
= 346.125 m
c ) It is not surprising as energy gained due to gravitational force by the earth is enormous . So component of energy gained due to gravitational force far exceeds the initial kinetic energy . Still in a competitive event , the fractional initial kinetic energy may be the deciding factor .
<span>Every 10s 5 waves; t1 = 2s for each wave
When v = 1.5m/s, 3 waves in 10s t2 = 10 / 3s
Calculating the frequency in first case f1 = 5 / 10 = 0.5
Calculating the frequency in second case f2 = 3 / 10 = 0.3
Using the Doppler formula f = (1-v/c) f0
For the formula f = f2, v = velocity of boat= 1.5 m/s, f0 = f1, c is velocity of wave
0.3 = 0.5 x (1 - 1.5/c) => 1.5/c = 1 - 0.6 => 1.5/c = 0.4 => c = 1.5/0.4
Velocity of the wave = 3.75 m/s</span>
Explanation:
Acceleration. Angular acceleration: Is the rate of change of the angular velocity of a body with respect to time.
Force. Torque: Is also called rotational force, since an applied torque will change the rotational motion of a body.
Mass. Moment of inertia: It is the resistance that opposes a body to rotates.
Work. Work: In a rotational motion, the work is done by the torque.
Translational kinetic energy. Rotational kinetic energy: is the kinetic energy due to the rotational motion of a body.
Linear momentum. Angular momentum: Represents the quantity of rotational motion of a body.
Impulse. Angular impulse: Is the change in angular momentum of a body.