Answer:
a)
, b) 
Explanation:
a) The magnetic force experimented by a particle has the following vectorial form:

The charge of the electron is equal to
. Then, cross product can be solved by using determinants:

The magnetic force is:

b) The charge of the proton is equal to
. Then, cross product has the following determinant:

The magnetic force is:

In the freezing physical change, when 210.0 g of water a 0 degrees freezes into ice, it gives off 71.0 kJ of heat.
<h3>What is freezing?</h3>
It is a physical change in which liquids give off heat to form solids.
We have 210.0 g of water at 0°C. We can calculate the amount of heat given off when it freezes into ice using the following expression.
Q = ΔH°fus × m
Q = 0.334 kJ/g × 210.0 g = 70.1 kJ
where,
- Q is the heat released.
- ΔH°fus is the latent heat of fusion.
- m is the mass.
In the freezing physical change, when 210.0 g of water a 0 degrees freezes into ice, it gives off 71.0 kJ of heat.
Learn more about freezing here: brainly.com/question/40140
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pulling farther back on the string
Explanation:
pulling back will increase kinetic energy
Answer:

Explanation:
given,
Radius of earth = 6400 Km
speed of a physics student in Miami, Florida, at latitude 26° = v
time period of rotation = 24 hour = 24 × 3600
= 86400 s
distance = speed × time



hence, the velocity of the student is equal to
Chemical indicator, any substance that gives a visible sign, usually by a colour change, of the presence or absence of a threshold concentration of a chemical species, such as an acid or an alkali in a solution. An example is the substance called methyl yellow, which imparts a yellow colour to an alkaline solution.