I have been teaching with various schools, colleges, universities and academies since 2010
(I) What is the activity of a sample of $\frac{14}{6} \mathrm{C}$ that contains $3.1 \times 10^{20}$ nuclei?
(II) Calculate the activity of a pure $9.7-\mu \mathrm{g}$ sample of 32 $\mathrm{P}$ $T_{\frac{1}{2}}=1.23 \times 10^{6} \mathrm{s} ) .$
(II) The activity of a sample of 35 $\mathrm{S}\left(T_{\frac{1}{2}}=7.55 \times 10^{6} \mathrm{s}\right)$ is $2.65 \times 10^{5}$ decays per second. What is the mass of the sample?
(II) A sample of $\frac{233}{92} \mathrm{U}\left(T \frac{1}{2}=1.59 \times 10^{5} \text { yr) contains }\right.$ $7.50 \times 10^{19}$ nuclei. (a) What is the decay constant? (b) Approximately how many disintegrations will occur per minute?
(II) A sample of 49 $\mathrm{K}$ is decaying at a rate of $6.70 \times 10^{2}$ decays/s. What is the mass of the sample?
Give 4 examples of implications, and for each write down theircontrapositive. Have two be real-world examples, and two be mathexamples.
(4) An oil gusher shoots crude oil 25 m vertically into theair through a vertical pipe having 0.100 m diameter. What is theflow rate in the pipe? (5 points)
A circuit contains a battery and two identical bulbs in series. How will the brightness of the bulbs compare? How does the current compare? After this, draw a diagram where a battery drives two bulbs in series rhat is connected in parallel with one additional bulb.
A 65 kg sky diver who has deployed her parachute and reachedterminal velocity descends the final 100 m of her jump in 15 s.Assume that her parachute has a circular cross-section of radius 4m and the density of the air is 1.3 kg/ m 3 .Find the drag coefficient of her parachute.Commentary: Depending on the random numbers generated for yourproblem, you may find a drag coefficient greater than 1.0. Theseare plausible values.
Take a look at this image. The skeleton with mass of 51.8 kgsits 57 cm from the balance point (d1). A forceF2 is applied on the other side of the seesaw at 4m from the balance point (d2). Can you find the force(F2) that will balance the seesaw? Report to one decimalpoint.
A wave on a string has the formula y = 0.030sin(0.55x - 62.8t + π/3). What is the wavelength, frequency, period, phase constant, and speed of the wave? The string has a linear density μ = 0.020 kg/m. What is the tension in the string? What is the rate of energy flow of the wave? Sketch the reference circle, the snapshot graph at t = 0, and the history graph at x = 0.
