Answer:
W = 1250 J = 1.25 KJ
Explanation:
The work done by the boy is due to the change in the position of the cement vertically. Hence, the work done in this case will be equal to the potential energy of the cement:
where,
W = Work done = ?
mg = W = weight of cement = 500 N
h = height covered = 2.5 m
Therefore,
<u>W = 1250 J = 1.25 KJ</u>
Answer:
ok
Explanation:
The Earth is made of several subsystems or "spheres" that interact to form a complex and continuously changing whole called the Earth system. Scale
Processes operating in the Earth system take place on spatial scales varying from fractions of millimeters to thousands of kilometers, and on time scales that range from milliseconds to billions of years.
Examples of instantaneous - breathing; rotation of the Earth; earthquake
Examples of long term - making coal; plate tectonics
Cycles
The Earth system is characterized by numerous overlapping cycles in which matter is recycled over and over again. Cycles involve multiple spheres and systems interactions.
Examples of cycles: day and night; rock cycle; seasons
Energy
The Earth system is powered by energy from two major sources: the Sun and the planet's internal heat.
Humans and the Earth System
People are part of the Earth system and they impact and are impacted by its materials and processes.
Answer:
The surface gravity is inversely proportional to the square of the radius of the planet
Explanation:
The gravity at the surface of a planet is given by:
where
G is the gravitational constant
M is the mass of the planet
R is the radius of the planet
We see from the formula that the surface gravity is inversely proportional to the square of the radius of the planet, R.
At the Earth's surface, the value of the surface gravity is approximately 9.81 m/s^2.
Answer:
chemical to nuclear and radiant
