Answer:
B. Gravity and air resistance
Explanation:
Experimentation has proven that :
When the parachute opens, air resistance becomes much greater than gravity. The forces are no longer balanced and this changes the
speed
Force between two charges is given by

here force is inversely depends on the square of the distance
so here if distance is decreased the force will increase'
now if force is tripled

initially distance between charges was 8.45 cm



so the distance between charges is 4.88 cm now
Answer:
The pressure is 
Explanation:
From the question we are told that
The gauge pressure at the mouth is 
The radius of the column is 
The speed of the liquid outside the body is 
The area of the column is 
The area inside the mouth 
Generally according to continuity equation

=> 
=> 
=> 
So

=> 
=> 
substituting values


Now the height of inside the mouth is 
Now the height of the column is 
Generally according to Bernoulli's equation
![p_1 = [\frac{1}{2} \rho v_2^2 + h_2 \rho g +p_2] -[\frac{1}{2} \rho * v_1^2 + h_1 \rho g ]](https://tex.z-dn.net/?f=p_1%20%3D%20%20%5B%5Cfrac%7B1%7D%7B2%7D%20%20%5Crho%20v_2%5E2%20%2B%20h_2%20%5Crho%20g%20%2Bp_2%5D%20-%5B%5Cfrac%7B1%7D%7B2%7D%20%5Crho%20%2A%20v_1%5E2%20%2B%20h_1%20%5Crho%20g%20%5D)
Now
which is the density of water
is the gauge pressure of the atmosphere which is zero
So
![p_1 = [(0.5 * 1000 * (3.1)^2) +(0.008 * 1000 * 9.8) + 0]-](https://tex.z-dn.net/?f=p_1%20%3D%20%20%5B%280.5%20%2A%201000%20%2A%20%283.1%29%5E2%29%20%2B%280.008%20%2A%201000%20%2A%209.8%29%20%2B%200%5D-)

Answer:
★The second law of refraction
The ratio of sine of angle of incidence to the sine of angle of refraction is a constant for a light of given colour and for a given pair of media. This law is also called Snell's law of refraction. If 'i' is the angle of incidence and 'r' is the angle of refraction then, Sin i/Sin r = constant
This constant value is called the refractive index of the second medium with respect to the first.