Fig. 4,1 (a) On Fig. 4.1.
(i) mark the direction of movement of the student's hand,
Ξ Ξ Ξ
(ü) mark and label the wavelength of the wave,
(ii) mark and label the amplitude A of the wave.
(b) Describe how the frequency of the wave is found using a stopwatch.
[2]
(c) Using the same rope, the student produces a wave of a longer wavelength than that shown in
Fig. 4.1.
Slate how the student does this.

double the distance = divide strength by 4

air exerts forces on falling objects near earth’s surface.

explanation:

the term 'free falls' refer to object that are falling towards the earth, in a situation in which gravity is the only force acting on the object.

for an object in free fall, the acceleration is constant (g, the gravitational acceleration), and so the velocity of the object constantly increases.

for objects near earth's surface, there is always another force acting on the object: the resistance due to the air. this force is opposed to the direction of fall of the object, and it is proportional to the velocity of the object, so as the object falls down, this force increases up to a point when it balances the force of gravity, and the object continues its motion at constant velocity (called terminal velocity). since in this case gravity is not the only force acting on the object, we are not in a situation of free fall.

that would be because of both gravity and friction. so     c