Answer:
1.65
Explanation:
The equation of the forces along the horizontal direction is:
(1)
where
F = 65 N is the force applied with the push
is the frictional force
m = 4 kg is the mass
is the acceleration
The force of friction can be written as 
(2), where
is the coefficient of kinetic friction
R is the normal force exerted by the floor
The equation of forces along the vertical direction is
(3)
since the bookcase is in equilibrium. Substituting (2) and (3) into (1), we find
And solving for ,
They make your muscles stronger and keep the bones, heart, and lungs in good condition. It implies that you have less chance of blood clotting and heart attack. one can balance his mood well and is likely to experience less stress in life.It also helps us to practice discipline.
<h3><u>Answer;</u></h3>
- A moving electric charge creates a magnetic field at all points in the surrounding region.
- An electric current in a conductor creates a magnetic field at all points in the surrounding region.
- A permanent magnet creates a magnetic field at all points in the surrounding region.
<h3><u>Explanation;</u></h3>
- A magnetic field can be created by running electricity through a wire. All magnetic fields are created by moving charged particles. it is important to also note that charged particles create magnetic fields only when they are moving.
- The strength of the magnetic field generated or created is proportional to the amount of current flowing through the wire. Thus, increasing the current increases the strength of the magnetic field.
I believe the sun is the primary source of energy for Earth's weather system. The sun is the primary energy source for Earth's climate system which is the first set of essential principles of climate sciences. Additionally, it is the primary source that drives all weather events, including precipitation, hurricane and tornadoes. The sun drives the hydrologic cycle, and makes life on Earth possible.
