Answer:
0.913
Explanation:
k.e=1/2mv square
k.e=1/2×0.078g×23.4256m/s square
k.e=0.913J
Cellular phones use D. microwaves.
Assume <em>R</em> is measured in meters (m) and <em>M</em> in kilograms (kg). Then
<em>R</em> ² / (<em>GM</em>) = [m]² / ([N•m²/kg²] [kg]) = m•kg / N = m•kg / (kg•m/s²) = s²
so <em>t</em> ² is indeed proportional to <em>R</em> ²/(<em>GM</em>).
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.