The 20-cm-diameter disk in the figure can rotate on an axle through s center. (Figure 1) You may want to review (Pages 321 - 325) Part A For help with math skills, you may want review: The Vector Cross Product What is the net torque about the axle? For general problem-solving tips and strategies for this topic, you may want to view a Video Tutor Solution of Nutcracker. Express your answer to two significant figures and include the appropriate units. Value Units Submit Request Answer Provide Feedback Figure < 1 of 1> 30 N. +30 N 457 5 cm 5 cm 20 N 20 N

I am unsure if I should determine how many miles equal a kilometer or how many miles per hour equal kilometers per hour. A car travels with an average speed of 35 MPH. What is this speed in km/h?

The arctic tern migrates farther than any other bird. Suppose the tern travels 16513 km south, only to encounter bad weather. Instead of trying to fly around the storm, the tern turns around and travels 617 km north to wait out the storm. It then turns around again immediately and flies 14814 km south to Antarctica. What is the tern's average speed in km/h if it makes this trip in 144 days? (Please round your answer to two decimal place; DO NOT include units)

Still think that unit conversion isn't important? Here is a widely publicized, true story about how failing to convert units resulted in a huge loss. In 1998, the Mars Climate Orbiter probe crashed into the surface of Mars, instead of entering orbit. The resulting inguiry revealed that NASA navigators had been making minor course corrections in SI units, whereas the software written by the probe's makers implicitly used British units. In the United States, most scientists use Sl units, whereas most engineers use the British, or Imperial, system of units. (Interestingly, British units are not used in Britain.) For these two groups to be able to communicate to one another, unit conversions are necessary. The unit of force in the SI system is the newton (N), which is defined in terms of basic Sl units as 1 N=1 kg · m/s?. The unit of force in the British system is the pound (lb), which is defined in terms of the slug (British unit of mass), foot (ft), and second (s) as 1 lb =1 slug ·…