Questions asked
Leon Druch
Numerade educator
Use the following information to answer the next ten exercises. On a baseball team, there are infielders and outfielders. Some players are great hitters, and some players are not great hitters. Let I = the event that a player in an infielder. Let O = the event that a player is an outfielder. Let H = the event that a player is a great hitter. Let N = the event that a player is not a great hitter Write the symbols for the probability that a player is not an outfielder.
Paul Gabriel
A computer is reading data from a rotating CD-ROM. At a point that is 0.030 m from the center of the disc, the centripetal acceleration is 120 $\mathrm{m} / \mathrm{s}^{2}$ What is the centripetal acceleration at a point that is 0.050 m from the center of the disc?
On a spacecraft, two engines are turned on for 684 ${s}$ at a moment when the velocity of the craft has $x$ and $y$ components of $v_{0 x}=4370 {m} / {m} / {s}$ and $v_{0 y}=6280 {m} / {s}$ s. While the engines are firing, the craft undergoes a displacement that has components of $x=4.11 \times 10^{6} {m}$ and $y=6.07 \times 10^{6} {m} .$ Find the $x$ and $y$ components of the craft's acceleration.
Jimmy Yao
Use similar triangles to find the coordinates of the point $Q$ that divides the segment from $P_{1}\left(x_{1}, y_{1}, z_{1}\right)$ to $P_{2}\left(x_{2}, y_{2}, z_{2}\right)$ into two lengths whose ratio is $p / q=r .$
David Mccaslin
The number $N$ (in millions) of US cellular phone subscribers is shown in the table. (Midyear estimates are given.) $$\begin{array}{|c|c|c|c|c|c|}\hline t & {1996} & {1998} & {2000} & {2002} & {2004} & {2006} \\ \hline N & {44} & {69} & {109} & {141} & {182} & {233} \\ \hline\end{array}$$ (a) Use the data to sketch a rough graph of $N$ as a function of $t$ (b) Use your graph to estimate the number of cell-phone subscribers at midyear in 2001 and $2005 .$
A proton and an alpha particle are released from rest when they are 0.225 nm apart. The alpha particle (a helium nucleus) has essentially four times the mass and two times the charge of a proton. Find the maximum speed and maximum acceleration of each of these particles. When do these maxima occur, just following the release of the particles or after a very long time?
Stephen Ho
Which will have the greater number of ions, 1 mol of nickel(II) or 1 mol of copper(I)?
Teresa Fuston
In the following exercises, solve using the problem-solving strategy for word problems. Remember to write a complete sentence to answer each question. Three-fourths of the people at a concert are children. If there are 87 children, what is the total number of people at the concert?
Umar Sohail Qureshi
A particle of mass $m=$ 1.18 $\mathrm{kg}$ is attached between two identical springs on a frictionless, horizontal tabletop. Both springs have spring constant $k$ and are initially unstressed, and the particle is at $x=0$ . (a) The particle is pulled a distance $x$ along a direction perpendicular to the initial configuration of the springs as shown in Figure $\mathrm{P} 7.66$ . Show that the force exerted by the springs on the particle is $$\overrightarrow{\mathbf{F}}=-2 k x\left(1-\frac{L}{\sqrt{x^{2}+L^{2}}}\right) \hat{\mathbf{i}}$$ (b) Show that the potential energy of the system is $$U(x)=k x^{2}+2 k L\left(L-\sqrt{x^{2}+L^{2}}\right)$$ (c) Make a plot of $U(x)$ versus $x$ and identify all equilibrium points. Assume $L=1.20 \mathrm{m}$ and $k=40.0 \mathrm{N} / \mathrm{m} .$ (d) If the particle is pulled 0.500 $\mathrm{m}$ to the right and then released, what is its speed when it reaches $x=0$ ?
In Exercises 33–36, find the value of $x$ and the value of $y$ for which $(x, 14)$ and $(18, y)$ are points on the graph. $$y=0.5 x+12$$