$$\text{The position of a particle $x(t)$ as a function of time $(t)$is described by}$$$$\text{the equation: $x(t)=2.0+3.0 t-t^3$, where $x$ is in $\mathrm{m}$ and $\mathrm{t}$ is in $\mathrm{s}$.}$$

$$\text{What is the maximum positive position of the particle on the $x$ axis?}$$

$$\text{A) $5.0 \mathrm{~m}$ }$$
$$\text{B) $2.0 \mathrm{~m}$ }$$
$$\text{C) $3.0 \mathrm{~m}$ }$$
$$\text{D) $1.0 \mathrm{~m}$ }$$
$$\text{E) $4.0 \mathrm{~m}$ }$$

$$\text{Two cars are $150 \mathrm{~km}$ apart and traveling toward each other. One car is }$$\text{ moving at $60 . \mathrm{km} / \mathrm{h}$ and the other is moving at 40 . $\mathrm{km} / \mathrm{h}$ }$$.$$\text{ In how many hours will they meet?}$$

$$\left(1\right.\text{ nano } \left.=10^{-9}\right)$$

$$\text{1 shake} =10^{-8}\text{ seconds.                                              }$$

$$\text{Find out how many nano seconds (ns) are there in 1 shake.}$$

$$\text{How many molecules of water are there in a cup containing } 250 \mathrm{~cm}^3 \text{ of water?}$$

$$\text{Molecular mass of $\mathrm{H}_2 \mathrm{O}=18 \mathrm{~g} / \mathrm{mole}$}$$

$$\text{Density of water $=1.0 \mathrm{~g} / \mathrm{cm}^3$}$$

$$\text{Avogadro s number $=6.02 \times 10^{23} \mathrm{molecules} / \mathrm{mole}$}$$

$$\text{A) $6.0 \times 10^{23}$ }$$

$$\text{B) $8.4 \times 10^{24}$ }$$

$$\text{C) $1.9 \times 10^{26}$}$$

$$\text{D) $3.7 \times 10^{28}$}$$

$$\text{E) $2.5 \times 10^3$}$$

$$\text{How many molecules of water are there in a cup containing } 250 \mathrm{~cm}^3 \text{ of water?}$$

$$\text{Molecular mass of $\mathrm{H}_2 \mathrm{O}=18 \mathrm{~g} / \mathrm{mole}$}$$

$$\text{Density of water $=1.0 \mathrm{~g} / \mathrm{cm}^3$}$$

$$\text{Avogadro s number $=6.02 \times 10^{23} \mathrm{molecules} / \mathrm{mole}$}$$

$$\text{A) $6.0 \times 10^{23}$ }$$

$$\text{B) $8.4 \times 10^{24}$ }$$

$$\text{C) $1.9 \times 10^{26}$}$$

$$\text{D) $3.7 \times 10^{28}$}$$

$$\text{E) $2.5 \times 10^3$}$$