Answer:
60 cm
Explanation:
We are given;
- Focal length of a concave mirror as 30.0 cm
- Object distance is 15.0 cm
We are required to determine the radius of curvature.
We need to know that the radius of a curvature is the radius of a circle from which the curved mirror is part.
We also need to know that the radius of curvature is twice the focal length of a curved mirror.
Therefore;
Radius of curvature = 2 × Focal length
Therefore;
Radius of curvature = 2 × 30 cm
= 60 cm
Check the 1st 2nd 3rd and 4th boxes
Answer:
Since the ball becomes positively charged, it will repel as like charges repel.
The deceleration experienced by the gymnast is the 9 times of the acceleration due to gravity.
Now from Newton`s first law, the net force on gymnast,

Here, W is the weight of the gymnast and a is the acceleration experienced by the gymnast (
acceleration due to gravity)
Therefore,
OR 
Given
and
Substituting these values in above formula and calculate the force exerted by the gymnast,

