Amount of carbon dioxide and energy when exercise

If angle "a" is 25°, angle "b" is: a) equal to angle c b) less than angle c c) greater than angle c

What is the coefficient of kinetic friction μk between the block and the tabletop?

Along wire carrying a 4.2 a current perpendicular to the xy-plane intersects the x-axis at x=−1.7cm. a second, parallel wire carrying a 3.0 a current intersects the x-axis at x=+1.7cm. part a at what point on the x-axis is the magnetic field zero if the two currents are in the same direction? express your answer to two significant figures and include the appropriate units.