Answer:
44J
Explanation:
Given parameters:
Mass of rock = 0.22kg
Initial velocity = 20m/s
Distance moved = 10m
Unknown:
Initial kinetic energy of the rock = ?
Solution:
To solve this problem, we need to understand that kinetic energy is the energy due to the motion of a body.
It is mathematically expressed as;
Kinetic energy = 
m v²
m is the mass
v is the velocity
Kinetic energy = x 0.22 x 20² = 44J
Answer:
An Element
Explanation:
Such substance cannot be an element because an element cannot be chemically disintegrated (i.e it cannot be disintegrated via chemical reaction).
Answer: apparent weighlessness.
Explanation:
1) Balance of forces on a person falling:
i) To answer this question we will deal with the assumption of non-drag force (abscence of air).
ii) When a person is dropped, and there is not air resistance, the only force acting on the person's body is the Earth's gravitational attraction (downward), which is the responsible for the gravitational acceleration (around 9.8 m/s²).
iii) Under that sceneraio, there is not normal force acting on the person (the normal force is the force that the floor or a chair exerts on a body to balance the gravitational force when the body is on it).
2) This is, the person does not feel a pressure upward, which is he/she does not feel the weight: freefalling is a situation of apparent weigthlessness.
3) True weightlessness is when the object is in a place where there exists not grativational acceleration: for example a point between two planes where the grativational forces are equal in magnitude but opposing in direction and so they cancel each other.
Therefore, you conclude that, assuming no air resistance, a person in this ride experiencing apparent weightlessness.
Answer:0.2mm
Explanation:
The length of one VSD=8/10=0.8mm
The least count of the instrument is the difference between the length of one MSD and length of one VSD
The length of inebriated MSD=1mm
Therefore,
The least count=1-0.8=0.2mm
