A circular loop with a radius of 0.28 m is rotated by 90.0 degree over 0.150 s in a uniform magnetic field with B = 1.40 T. The plane of the loop is initially perpendicular to the field and is parallel to the field after the rotation. (a) What is the average induced emf In the loop?
(b) If the rotation is then reversed, what is the average induced emf in the loop?

The astronauts on the space shuttle flights experienced an acceleration of 29 m/s2 (about 3 "g's") during lift-off. what upward force must the astronaut's seat apply to the astronaut in order to cause this acceleration? assume the astronaut's mass is 70 kg, and compute this force when the acceleration is near the earth's surface so their weight equals latex: mg m g .