Question

In: Physics

Elena runs the 100m dash in 10.4s. If she does this by spending the first 3s...

Elena runs the 100m dash in 10.4s. If she does this by spending the first 3s of the race accelerating and then maintaining her top speed (constant velocity) for the rest of the race: What acceleration did she experience? What was her top speed?

Expert Solution

We have,
Let top speed be , initial speed , and acceleration be .

We have total distance , total time .

Let distance covered by Elena in of acceleration be .

Then distance covered at top speed .

Also, from the kinematics formula,

Because Elena starts running from rest, her initial speed

From the kinematics formula

Substituting value from equation (3) and (2) into equation (1):

Therefore, Elena's acceleration is .

Now substituting the value of acceleration into equation (2):

Therefore, Elena's velocity is .

genius_generous answered 2 years ago

1. The time for a squirrel to run the 100m dash is normally distributed with μ=...

1. The time for a squirrel to run the 100m dash is normally distributed with μ= 18.6 seconds and σ =.8 seconds.Suppose that Daniel can run a 100m dash in 17.0 seconds. (a)Draw a sketch of the distribution. (b)What proportion of squirrels can run the 100m dash faster than Daniel? (c)(Di and Jane run the 100m dash in 18 and 19 seconds respectively. What is the combined proportion of squirrels who run the 100m dash either A) faster than both...

8. Elena just got engaged to be married. She posts a message about the engagement on...

8. Elena just got engaged to be married. She posts a message about the engagement on Facebook. Three of her friends, Alicia, Barbara, and Charlene, will click “like" on her post. Use X, Y, and Z (respectively) to denote the waiting times until Alicia, Barbara, and Charlene click “like" on this post, and assume that these three random variables are independent. Assume each of the random variables is an Exponential random variable that has an average of 2 minutes. 8a....

Andy runs a small pottery firm. in her first year she hired one helper at 12,000...

Andy runs a small pottery firm. in her first year she hired one helper at 12,000 per year, paid annual rent of $5,000 for her shop, and spent $20,000 on material. she has 40,000 of her own funds invested in equipment that could earn her $4,000 per year if alternatively invested. she had been offered $15,000 per year to work as a Potter for a competitor she estimates her entrepreneurial talents are worth $3,000 per year. total annual revenue from...

Draw a dash-wedge structure for (2S,3R)-3-bromo-6,6-dimethylocta-7-en-2-ol. Draw a dash-wedge structure for (3S,4R)-4-chloro-3,5-dimethylhex-1-yne.

A woman runs 50 meters at 54 degrees north of east. She then runs 40 meters...

A woman runs 50 meters at 54 degrees north of east. She then runs 40 meters at 47 degrees north of east. She then runs 34 meters south of east at 30 degrees. What would her displacement be? Draw, explain, and show your work.

Jenna runs a small boutique in Capitola. She tells one of her suppliers that she is...

Jenna runs a small boutique in Capitola. She tells one of her suppliers that she is willing to pay $6 for a pair of wool hand warmers and not a dime more. On the basis of this information, what can you conclude about her price elasticity of demand for wool hand warmers? Group of answer choices It is somewhat elastic. It is perfectly elastic. It is perfectly inelastic. The price elasticity coefficient is 0.

1 How does the spending by government and the taxes used to finance that spending affect...

1 How does the spending by government and the taxes used to finance that spending affect the overall economy? 2 Explain how low interest rates impact banks compared to consumers

Why does a 3s electron in Al experience a greater effective nuclear charge than a 3p...

Why does a 3s electron in Al experience a greater effective nuclear charge than a 3p electron? the maxima radial probability of finding the electron in a 3p orbital is smaller than for the 3s orbital the maxima radial probability of finding the electron in a 3s orbital is smaller than for the 3p orbital the minima radial probability of finding the electron in a 3s orbital is smaller than for the 3p orbital the maxima radial probability of finding...

Does the expenditure approach to computing GDP measure U.S. spending on all goods, U.S. spending on...

Does the expenditure approach to computing GDP measure U.S. spending on all goods, U.S. spending on only U.S. goods, or U.S. and foreign spending on only U.S. goods? Explain your answer.

(A). The number of home runs that Mark McGuire hit in the first 13 years of...

(A). The number of home runs that Mark McGuire hit in the first 13 years of his major league baseball career are as follows {3, 49, 32, 33, 39, 22, 42, 9, 9, 39, 52, 58, 70} Construct a stem-and-leaf plot for the data. (B). A random sample of 32 high school students is selected. Each student is asked how much time he or she spent on the internet during the previous week. The times, in hours, are listed in...