Answer:
Cardboard, Paper towels, Food waste, and wooden based items
To solve this problem, we apply the concepts related to the sum of forces and balance in a diagram that will be attached, in order to identify the behavior, direction and sense of the forces. The objective is to find an expression that is in terms of the mass, the angle, the coefficient of friction and the length that allows us to identify when the ladder begins to slip. For equilibrium of the ladder we have,



Now we have that


And for equilibrium of the two forces we have finally

Rearranging to find the distance,


So if we have that the frictional force is equivalent to




With this value we have that


Therefore can go around to 5.19m before the ladder begins to slip.
To solve this problem we will apply the concepts related to Orbital Speed as a function of the universal gravitational constant, the mass of the planet and the orbital distance of the satellite. From finding the velocity it will be possible to calculate the period of the body and finally the gravitational force acting on the satellite.
PART A)

Here,
M = Mass of Earth
R = Distance from center to the satellite
Replacing with our values we have,



PART B) The period of satellite is given as,




PART C) The gravitational force on the satellite is given by,




The frequency of the wave will not change. Since the change in medium doesn't affect the source of the waves, the frequency of those waves do not change.
Hope this helps! :)
When solar radiation reaches the Earth it quickly dissipates as most of the radiation and UV rays are blocked by ozone layer, but more radiation and UV rays are able to get through because of global warming.