Explanation:
Let us calculate the work done in lifting an object of mass m through a height h, such as in Figure 1. If the object is lifted straight up at constant speed, then the force needed to lift it is equal to its weight mg. The work done on the mass is then W = Fd = mgh. We define this to be the gravitational potential energy (PEg) put into (or gained by) the object-Earth system. This energy is associated with the state of separation between two objects that attract each other by the gravitational force
Potential energy is a property of a system rather than of a single object—due to its physical position. An object’s gravitational potential is due to its position relative to the surroundings within the Earth-object system. The force applied to the object is an external force, from outside the system. When it does positive work it increases the gravitational potential energy of the system. Because gravitational potential energy depends on relative position, we need a reference level at which to set the potential energy equal to 0. We usually choose this point to be Earth’s surface, but this point is arbitrary; what is important is the difference in gravitational potential energy, because this difference is what relates to the work done. The difference in gravitational potential energy of an object (in the Earth-object system) between two rungs of a ladder will be the same for the first two rungs as for the last two rungs.
Answer:
The tension on the string is 
Explanation:
From the question we are told that
The mass of the rock is 
The density of the rock is 
Generally the volume of the rock is mathematically evaluated as
substituting values
The volume of the rock immersed in water is
substituting values
mass of water been displaced by the this volume is
According to Archimedes principle
=> 
The weight of the water displace is
The actual weight of the rock is
The tension on the string is
substituting values
The viscous force on an object moving through air is proportional to its velocity.
The only forces acting on an object when falling are air resistance and its weight itself. The weight acts vertically downwards whereas air resistance acts vertically upward.
Let F be the viscous force due to air molecules, B be buoyant force due to air and W be the weight of falling object. Initially, the velocity of falling object and hence the viscous force F is zero and the object is accelerated due to force
(W-B). Because of the acceleration the velocity increases and accordingly the viscous force also increases. At a certain instant, the viscous force becomes equal to W-B. The net force then becomes zero and the object falls with constant velocity. This constant velocity is called terminal velocity.
Thus at terminal velocity, air resistance and force of gravity becomes equal.
Mass is a body of matter of indefinite shape and considerable size. Density is the degree to which something is filled. Check this website for more a better understanding : <span>www.answers.com/Q/What_is_the_relationship_between_density_and_volume</span>
Gravity is the force that attracts all matter to each other.
Explanation:
Sir Isaac Newton discovered Gravity when he saw a falling apple while thinking about the forces of nature.
Gravity is a fundamental force that causes objects to have weight. Gravity acts on all matter and is a function of both mass and distance. Each object attracts every other object with a force that is proportional to the product of their masses and inversely proportional to the square of the distance between them. The force of attraction is, however, negligible between most objects because of their small size.
Gravitational force is given as:
Where G is gravitational constant and is equal to 6.674×10−11 m³⋅kg⁻¹⋅s⁻²
m₁ and m₂ are the masses of the two objects.
r is the distance between the two objects.
The gravity is what makes an apple fall on the ground and gravity is the force that keeps us on the ground.
Keywords: gravity, Newton, Force, weight
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