Answer:
Both physical and chemical changes
Explanation:
From the definition of the law of conservation of mass, total mass of all the substances taking part in a chemical reaction is conserved and the number of atoms of each element in the reaction does not change when a new product is formed. Both physical and chemical changes follow the law since when the system is closed to all transfers of matter and energy, the mass of the system must remain constant over time, irrespective of the state.
Cheimcal engery is related to positions of atoms within molecules..
Answer:
Explanation:
For this problem we must use Newton's second law where force is gravitational attraction
F = m a
Since movement is circular, acceleration is centripetal.
a = v2 / r
Let's replace
G m M / r² = m v² / r
G M r = v²
The distance r is from the center of the planet
r = R + h
v = √ GM / (R + h)
If the friction force is not negligible
F - fr = m a
Where the friction force must have some functional relationship, for example
Fr = b v + c v² +…
Suppose we are high enough for the linear term to derive the force of friction
G m M / r - (m b v + m c v2) = m v2
G M / r - b v = v²
We see that the solution of the problem gives lower speeds and that change over time.
To compensate for this friction force, the motors should be intermittently suspended to recover speed.
The weight of the object moving and the roughness of the surfaces
Answer:
Magnitude of vector A is 51.4 m
The angle of vector A with positive x-axis is θ= 
Explanation:
Given is
=-31m
=41m
Let and are components of a vector A,
The magnitude of vector A will be:
= 
A = 51.4 m
we know
θ1= 
= 
=
Vector A is present in 2nd quadrant as x-component of vector A is negative and y-component is positive.
For finding the angle of vector with positive x-axis,
θ=180-52.9
θ=
