You want to place a mirror at a blind turn on the staircase in your house. which would be best suited for this purpose?
a. flat mirror
b. plane mirror
c. convex mirror
d. concave mirror

Convex Mirror

Explanation:

Convex mirror always form virtual and upright image so here at the position of blind turn we need a mirror which always form virtual and upright image to see the position of all objects on the other side correctly.

Now we have two options for such type of mirror condition

1) Plane Mirror

2) Convex Mirror

Since convex mirror has outward convex surface so here it will cover large field of view as compare to plat mirror so it is better to use Convex mirror at the position of blind turn.

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.