The blades that spin around in the fan, because they are flat and produce work
When you heat something of cool it down you don't change the substance you might change the why is looks, but it is still the same substance. For example you cool water to 0 degrees Celsius it turns into ice but it still is two parts hydrogen and one part oxygen H2O. Physical changes will change state and/or form but it will still be what it originally was on the molecular level. Hope that helped.
Answer:

Explanation:
As we know that initial speed of the fall of the stone is ZERO

also the acceleration due to gravity on Mars is g
so we have

now we have

now if the same is dropped for 4t seconds of time
then again we will use above equation



Answer: L can be expressed in terms of g and f as
L = g/(2πf)^2
Explanation: Please see the attachments below