Answer:
Be sure you understand two optics principles: the focal length of a convex mirror is NEGATIVE (by convention) and R / 2 = f.
Find f, take its negative, plug in the mirror equation and obtain Di = - 24 cm. This indicates that the image is virtual (as it should be in a convex mirror), is erect (as all virtual images are), is diminished (as it should be) and INSIDE the mirror as it should be.
Explanation:
Answer: The wheel's average rotational acceleration is -0.4 radians per second squared (rad/s^2)
Explanation: Please see the attachments below
On Earth, the period of a pendulum is given by:

where L is the length of the pendulum and

is the gravitational acceleration on Earth.
Similarly, the period of the same pendulum on Mars will be

where

is the gravitational acceleration on Mars.
Therefore, if we want to see how does the period of the pendulum on Mars change compared to the one on Earth, we can do the ratio between the two of them:

Therefore, the period of the pendulum on Mars will be 1.63 times the period on Earth.