A ball is thrown upward with a speed of approximately 30 ms. Which of the following sets of numbers are good estimates of the ball's velocity 1 second. 2 seconds and 3
seconds later?
a. -10 m/s. -10 m/s. -10 m/s
b. 30 m/s. 30 m s. 30 m/s
c. 40 m s. 50 m s. 60 m/s
d. 20 m s. 10 m s. Cms

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.