A frictional force f provides the centripetal force as a car goes around an unbanked curve of radius R at speed V. Later, the car encounters a similar curve, except of radius 0.5 R , and the driver continues around this curve at the same speed V . In order to make this second curve, the frictional force on the car must be equal to In order to make this second curve, the frictional force on the car must be equal to:

What can you increase the strength of an electromagnet by

Currents in dc transmission lines can be 100 a or higher. some people are concerned that the electromagnetic fields from such lines near their homes could pose health dangers. for a line that has current 150 a and a height of 8.0 m above the ground, what magnetic field does the line produce at ground level? express your answer in teslas and as a percentage of the earth’s magnetic field, which is 0.50 g. is this value cause for worry?

What are the dimensions of the cross section that passes through the points a, f, g, and d?