A particle travels along the curve from A to B in 5 s. It takes 8 s for it to go from B to C and then 10 s to go from C to A. Determine its average speed when it goes around the closed path.

5.1 m/s

Explanation:

The figure is missing: find it in attachment.

In order to find the average speed, we have to calculate the length of the total path, and divide it by the total time elapsed.

The curve from A to B is a quarter of a circle with a radius of r = 20 m, so its length is:

The path BC is the hypothenuse of a right triangle with sides equal to 20 m and 30 m, so its length is

Finally, the length of the path AC is the sum of the side of 30 m and the radius of the curve, so

So the total distance covered is

The total time elapsed is

So, the average speed is

the temperature and the pressure affect solubility. temperature affects by changing the properties of the solvent. the increase in pressure increases solubility, the decrease in pressure decreases solubility.

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.