Answer:
To derive the fourth equation of motion, first we have to consider the equation for acceleration and then to rearrange it. or v2 = u2 + 2as and this equation of motion can be used to find the final velocity or the distance travelled if the other values are given.
Explanation:
v= u + at
s =( u + v ) t /2
s = ut + at2/2
v2 = u2 + 2as
The net force = sum of all forces acting on the body
If we take left side as -ve and right side as +ve,
then,
The net force here would be equal to,
10N + (- 3N)
= 7N.
Therefore, a net force of +7N ( + indicates it's moving towards right) is acting on the book of mass 2kg.
B. Energy
A power company charges its customers for electricity based upon B. Energy.
<h3>
Explanation:</h3>
Kilo-watt Hours (kWh) is the unit that measures the electricity consumption of customers. Since Power is defined as the rate at which electrical energy is transferred by an electrical circuit per unit time,

If energy is transmitted at a constant rate over a period of time, the total energy in kilowatt hours is the product of power in kilowatts(kW) and time in hours (h)

Answer:
The increase in temperature of the bullet is 351.1 kelvin
Explanation:
First, we should find the kinetic energy of the bullet is:

with m the mass and v the velocity.

Now we know that half of the kinetic energy of the bullet is transformed into internal energy, by second's law of thermodynamics that means heat (Q) to raise bullet temperature (T), so:

To know what the increase in temperature is, we should use specific heat of lead:

The equation that relates specific heat, change in temperature and mass is:

solving for
:


Answer:
c. testing student opinions
Explanation:
opinions aren't factual and they would not aide an experiment if it wasn't for a social experiment.