Explanation:
Friction occurs because no surface is perfectly smooth. Rougher surfaces have more friction between them. Heavier objects also have more friction because they press together with greater force. Friction produces heat because it causes the molecules on rubbing surfaces to move faster and have more energy.
Answer:
The percentage uncertainty in the average speed is 0.10% (2 sig. fig.)
Explanation:
Consider the formula for average speed
.
,
where
is the total distance, and
is the time taken.
The percentage uncertainty of a fraction is the sum of percentage uncertainties in
- the numerator, and
- the denominator.
What are the percentage uncertainties in
and
in this question?
The unit of the absolute uncertainty in
is meters. Thus, convert the unit of
to meters:
.
.
The unit of the absolute uncertainty in
is seconds. Convert the unit of
to seconds:

Similarly,
.
The average speed
here is a fraction of
and
. Both
and
come with uncertainty. The percentage uncertainty in
will be the sum of percentage uncertainties in
and
. That is:
.
Generally, keep
- two significant figures for percentage uncertainties that are less than 2%, and
- one for those that are greater than 2%.
The percentage uncertainty in
here is less than 2%. Thus, keep two significant figures. However, keep more significant figures than that in calculations to make sure that the final result is accurate.
Answer:

Explanation:
Given:
- spring constant of the spring attached to the input piston,

- mass subjected to the output plunger,

<u>Now, the force due to the mass:</u>



<u>Compression in Spring:</u>



or

Electromagentic waves can travel through space. they don't require any medium.