2022-04-28

You can still ask an expert for help

asked 2021-03-21

A floating ice block is pushed through a displacement d=(15m)i-(12m)j along a straight embankment by rushing water, which exerts a force F=(210N)i-(150N)j on the block. How much work does theforce do on the block during the displacement?

asked 2020-10-21

An 80.0-kg skydiver jumps out of a balloon at an altitude of1000 m and opens the parachute at an altitude of 200 m. (a) Assuming that the total retarding force on the diver is constant at 50.0 N with the parachute closed and constant at 3600 N with the parachute open, what is the speed of the diver whenhe lands on the ground? (b) Do you think the skydiver will be injured? Explain. (c) At what height should the parachute be opened so that the final speed of the skydiver when he hits the ground is 5.00m/s? (d) How realistic is the assumption that the total retarding force is constant? Explain.

asked 2021-02-24

If the coefficient of static friction between your coffeecup and the horizontal dashboard of your car is, how fast can you drive on a horizontal roadwayaround a right turn radius of 30.0 m before the cup starts toslide? If you go too fast, in what direction will the cupslide relative to the dashboard?

asked 2021-01-06

A force acting on a particle moving in the xy plane is given by $F=(2yi+{x}^{2}j)N$, where x and y are in meters. The particle moves from the origin to a final position having coordinates x=4.65 m and y=4.65 m, as in Figure.

a) Calculate the work done by F along OAC

b) Calculate the work done by F along OBC

c) Calculate the work done by F along OC

d) Is F conservative or nonconservative?

asked 2020-11-20

In 2014, the Centers for Disearse reported the percentage of people 18 years of age and older who smoke. Suppose that a study designed to collect new data on smokers and nonsmokers uses a preliminary estimate of the proportion who smoke of 0.30.

a) How large a sample should be taken to estimate the proportion of smokers in the population with a margin of error of 0.02? Use 95% confidence.(Round your answer up to the nearest integer.)

b)Assume that the study uses your sample size recommendation in part (a) and finds 470 smokers. What is the point estimate of the proportion of smokers in the population? (Round your answer to four decimal places.)

c) What is the 95% confidence interval for the proportion of smokers in the population? (Round your answer to four decimal places.)

a) How large a sample should be taken to estimate the proportion of smokers in the population with a margin of error of 0.02? Use 95% confidence.(Round your answer up to the nearest integer.)

b)Assume that the study uses your sample size recommendation in part (a) and finds 470 smokers. What is the point estimate of the proportion of smokers in the population? (Round your answer to four decimal places.)

c) What is the 95% confidence interval for the proportion of smokers in the population? (Round your answer to four decimal places.)

asked 2022-03-30

I have worked an integral and reduced the integral to

$\frac{n\pi +\mathrm{sin}\left(\frac{n\pi}{2}\right)-\mathrm{sin}\left(\frac{3\pi n}{2}\right)}{2n\pi}$

asked 2022-01-14

How to show f′(0) exists for $f\left(x\right)={e}^{\frac{-1}{{x}^{2}}}\mathrm{sin}\left(\frac{1}{x}\right)$ for $x\ne 0$ and f(0)=0?