Question

Typing Speed In a typing class, the average number of (a) Use the res words per minute N typed after t weeks of lessons was found to be modeled by N=158/1+5.4e−⁰.¹²ᵗ​ Find the numbers of weeks necessary to type (a) 50 words per minute and (b) 75 words per minute. (b) Use a graj 150. Geology On the Richter scale, the magnitude R of an earthquake of intensity I is modeled by (c) Determine R=log₁₀​I/I₀(d) Use the mo of exercise where I₀​=1 is the minimum intensity used for comparison. Find the intensities I of the following earthquakes measuring R on the Richter scale. (a) R=8.4 (b) R=6.85 (c) R=9.1

Answer 1

To find the number of weeks needed to reach a certain typing speed, the provided model equation is used. For seismic events, earthquake intensity can be calculated using the Richter scale formula based on a given magnitude.

Step-by-step explanation:

Typing Speed Calculation

To calculate the number of weeks necessary to type at a certain speed, we use the given model N = 158 / (1 + 5.4e−​0.12t). By substituting the desired words per minute into the equation, we can solve for 't' to find the number of weeks needed.

Richter Scale and Earthquake Intensity

The Richter scale measures the magnitude of an earthquake, and the magnitude R is determined using the logarithmic formula R = log10(I/I0). To find the intensity I of earthquakes given their Richter scale values, we can rearrange the formula to I = 10R × I0 and calculate the respective intensities.