Velocity as a Vector Quantity
Because the person always returns to the original position, the motion would never result in a change in position. Since velocity is defined as the rate at which the position changes, this motion results in zero velocity.
When a star is moving away from earth it appears blue
When the same masses are heated by the same amount copper will heat up the fastest. Copper is a good conductor of heat that is why it easily heats up. Gold is not a good conductor of heat because of its stable properties.
Answer:

Explanation:
According to the free body diagram, in this case, we have:

Recall that the force of friction is given by:

Replacing and solving for the coefficient of kinetic friction:

We have an uniformly accelerated motion. Thus, the acceleration is defined as:

Finally, we calculate
:
