How does adding an iron bar to a solenoid affect the magnetic field of the electromagnet? It changes the magnetic field to a current. It changes the magnetic field’s direction. It increases the magnetic field’s strength. It decreases the magnetic field’s strength.

If an athlete runs once around a track, back to the starting line, her average velocity is zero. true or false?

Arunner is training for an upcoming marathon by running around a 100-m-diameter circular track at constant speed. let a coordinate system have its origin at the center of the circle with the x-axis pointing east and the y-axis north. the runner starts at (x, y) = (50 m, 0 m) and runs 2.5 times around the track in a clockwise direction.

Increasing the pressure on one spot of a fluid will increase the pressure everywhere else in the fluid a. pascals principal b. archimedes' principal c. bernoulli's principal