All Solutions
Page 29: Standardized Test Practice
dfrac{1m}{100cm}; dfrac{1,000m}{1km}
$$
86.2cm cdotdfrac{1m}{100cm}
$$
.862m cdot dfrac{1km}{1,000m}
$$
8.62 times 10^{-4} km
$$
a). $8.62 text{ m} times frac{100 text{ cm}}{1 text{ m}} = 862 text{ cm}$
b). $0.862 text{ mm} times frac{1 text{ cm}}{10 text{ mm}} = 0.0862 text{ cm}$
c). $8.62 times 10^{-4}text{ km} times frac{1000 text{ m}}{1 text{ km}} times frac{100 text{ cm}}{1 text{ m}} = 86.2 text{ cm}$
d). $862 text{ dm} times frac{10 text{ cm}}{1 text{ dm}} = 8620 text{ cm}$
Based on what he have solved, choice $boxed{C}$ is equal to 86.2 cm.
$$t = frac{d}{v} = frac{left[text{ km}right]}{[text{m/s}]} = frac{left[text{km s}right]}{left[text{m}right]}$$
Note that in order for the meter unit to cancel, we must multiply the numerator by 1000 to convert the kilometers to meter. Hence, the proper way to solve the time in seconds is to: divide the km by the m/s, then multiply by 1000, which is letter $boxed{B}$.
where $(x_{2},y_{2})$ and $(x_{1},y_{1})$ are points on lying on the line.
$(x_{2},y_{2}) = (8 m/s, 2 s)$
$slope=dfrac{(2-0)m/s}{(8-0)s}=dfrac{1}{4} m/s^{2}=0.25$ $m/s^{2}$
D = dfrac{m}{V}
$$
dfrac{VD}{D} =dfrac{m}{D}
$$
V = dfrac{m}{D}
$$
The m/m on the right side cancels out and you are left with
a = F/m
The conversion factor is $10^{-3}$, multiply the grams by the conversion factor to get the kilograms:
$350times$ $10^{-3}$ = 0.35 kg
Sub the given F and the m in kg and solve of a:
a = $dfrac{2.7}{0.35}$
= $7.71 m/s^{2}$
$therefore$ the acceleration is $7.7 m/s^{2}$
b) $10^{-3}$
c) $7.7 m/s^{2}$
textbf{underline{textit{Solution}}}
$$
$$
tag{1} y= -1.03 x + 11.54
$$
$textbf{Or }$we can just draw the line by hands which best fits all the points, and then find the slope from any 2 points on the best fit line with coordinates ($x_1,y_1$) and ($x_2,y_2$) through the following equation
$$
m = dfrac{y_2 – y_1}{x_2 – x_1}
$$
And then we find the point $c$ of $y$-intercept “that is it, the point where $x=0$”, and then substituting in the general equation of the straight line, where
$$
y=mx+c
$$
$textbf{underline{textit{note:}}}$ sometimes we get a physical situation, where the plot best fit line must pass through the origin, intercept at some value in $y$-axis in this problem we are free to chose the $y$-intercept which enables us to have the fitting curve which fits all the points with the least error.
Check, the following $textbf{Graph}$ where we plotted the points in the graph and draw the best fit line whose equation is given by (1)
y= -1.03 x + 11.54
$$