Earth's magnetic field is a strong force due to it's magnetic core. Which one of the following is NOT a way in which the magnetic field is used?

A) Used with a rock, Lodestone, as a compass.
B) Guiding Loggerhead Sea Turtles back to the sea.
C) Pushing magma up through the interior of earth.
D) Combining with particles from the sun's corona to create light shows at the poles.

Alead ball is dropped into a lake from a diving board 5m above the water . it hits the water with a certain velocity and then sink with constant velocity in bottom . it reaches the bottom 5 second after it is dropped if g= 10m/s2 . find depth of the lake and average velocity of the ball ?

Which of these metals are magnetic?

The particle p starts from rest at point a at time t = 0 and changes its speed thereafter at a constant rate of 2.8g as it follows the horizontal path shown. determine the magnitude and direction of its total acceleration (a) just before point b, (b) just after point b, and (c) as it passes point c. state your directions relative to the x-axis shown (ccw positive) and choose the angle with the smallest magnitude.