Answer:
The statement is true: velocity and acceleration have opposite directions in the interval of braking.
Explanation:
Let's say we have a velocity .
The acceleration is the rate of change of the velocity . This means that if is <em>increasing during</em> time, then must be positive. But if is <em>decreasing over</em> time, then will be negative (even though the velocity is positive).
Mathematically:
decreases ⇒
⇒.
Example:
Answer:
d. conduction
Explanation:
Conduction involves the transfer of electric charge or thermal energy due to the movement of particles. When the conduction relates to electric charge, it is known as electrical conduction while when it relates to thermal energy, it is known as heat conduction.
In the process of heat conduction, thermal energy is usually transferred from fast moving particles to slow moving particles during the collision of these particles. Also, thermal energy is typically transferred between objects that has different degrees of temperature and materials (particles) that are directly in contact with each other but differ in their ability to accept or give up electrons.
Any material or object that allow the conduction (transfer) of electric charge or thermal energy is generally referred to as a conductor. Conductors include metal, steel, aluminum, copper, frying pan, pot, spoon etc.
In conclusion, conduction typically involves the transfer of heat energy by direct contact between two or more conductors such as a pot and electric cooker.
They are derived from the planetary used in astrology
Use the equation, F= m(mass)x a (acceleration) to find the net force.
We can solve the problem by using the basic relationship between space (S), time (t) and velocity (v) of the uniform motion:
The duration of the first part of the trip is
And the velocity is
So we can find the distance covered during the first part of the trip by rearranging the previous equation:
The duration of the second part of the trip is 15 minutes (because the duration of the total trip is 30 minutes, and the duration of the first part is 15 minutes), so
and the velocity is
Therefore, the distance covered in this second part of the trip is
So, the total distance between the home and the school is