Answer:

Explanation:
This is a projectile motion problem. We will first separate the motion into x- and y-components, apply the equations of kinematics separately, then we will combine them to find the initial velocity.
The initial velocity is in the x-direction, and there is no acceleration in the x-direction.
On the other hand, there no initial velocity in the y-component, so the arrow is basically in free-fall.
Applying the equations of kinematics in the x-direction gives

For the y-direction gives

Combining both equation yields the y_component of the final velocity

Since we know the angle between the x- and y-components of the final velocity, which is 180° - 2.8° = 177.2°, we can calculate the initial velocity.

Answer:
Newtons law of universal gravitation is the phenomena in which Newton said that every particle in environment will attract other particles in the space.
Explanation:
Newton law of motion and gravitation attract forcefully which is direct proportional to the masses of the particles and inversely proportional to the square of the distances between the centers. Other physicist used Newtons law in research related to motion or to find out the distance between earth and sun. Because this law is about the mass of the objects. When the mas of an object is doubled, the force between the objects get too doubled. When the mass of the two objects is doubled the gravitational pull between these two objects gets doubled. Sir Isaac Newton first gave this law when see fall down an apple from tree.
Formula is : F = G Mm/r2 Here G is gravitational pull that is constant.
Gravitational potential energy is associated with the shape or position of an object.
1.)When an object is placed at height h above ground, gravitational potential energy associated with it is given by,
P.E = mgh
2.)In projectile motion during upward motion, kinetic energy of object is converted into potential energy.
This is the match:
1) stored energy related to positions of atoms within molecules ↔ chemical energy
Explanation: the chemical energy is the energy stored in the bonds that binds the atoms that form the molecules.
2) energy released when a nucleus splits or combines ↔ nuclear energy
Explanation: there is a huge energy inside an atom which may be released when nuclei suffer fusion (combination of nuclei) or fission (split of nuclei). The fusion of atoms is what happens in stars and it is the source of their energy. Fision of atoms is the nuclear energy used in the nuclear plants to produce electricity.
3) energy related to an object's movement ↔ motion energy
Explanation:
The motion energy is the kinetic energy, KE. KE = (1/2) m* v^2
4) energy related to heigth ↔ gravitaional potential energy
The higher an object is the higher its gravitational potential energy, PE.
PE = m*g*h.
5) energy related by vibration of a string ↔ sound energy
Explanation:
Sure you have seen that: when the string of a guitar vibrate the sound is produced.
6) energy of motion of particles in a substance ↔ thermal energy
The thermal energy is the product of the motions (vibration, translation and collisions) of the molecules that form the substance. The higher the motion the the higher the thermal energy measured as temperature.
Explanation:
Balanced forces will cause no change in the speed of an object.