Answer: the sun
Explanation:
The sun's radiant energy reaches the earth's surface either directly through radiation, indirectly through convection, or it can move "across" or "through" objects or materials on the surface via conduction. Let's look more closely at each case. We've probably experienced the feeling of "warmth" of the sun on our skin on a sunny day. Light energy from the sun is reaching us across space and down through the atmosphere through radiation. A dark colored vehicle in the sun quickly becomes warm (or hot!) to the touch because of radiation. The light energy from the sun heats the air in the earth's atmosphere, and this drives convection and transfers thermal energy around. It is possible that we've felt a "hot breeze" on our skin on sunny days. The thermal energy in the air will be carried to objects in its path, and it will warm them.
Answer:
This is because we are surrounded by positive ions from electromagnetic fields generated by computers, cell phones, and other electronic devices which can impair brain function and suppress the immune system causing symptoms such as: anxiety, breathing difficulty, fatigue, headaches, irritability, lack of energy, poor concentration, nausea, and vertigo,
Explanation:
Newton's second law states that the resultant of the forces applied to an object is equal to the product between the object's mass and its acceleration:

where in our problem, m is the mass the (child+cart) and a is the acceleration of the system.
We are only concerned about what it happens on the horizontal axis, so there are two forces acting on the cart+child system: the force F of the man pushing it, and the frictional force

acting in the opposite direction. So Newton's second law can be rewritten as

or

since the frictional force is 15 N and we want to achieve an acceleration of

, we can substitute these values to find what is the force the man needs:
According to the statements the number of electrons is 150, then
e = 150
But there is a positive charge of +22e, then the number of protons would be
p = 150+172
If the mass of the electrons is

And the mass of the protong is

We have that the total mass of the system would be


