A long straight wire carries 400 A. How far from the wire will the magnetic field generated equal that of earth (i. e. 3X 10-4 T)?

Abaseball picther can throw a ball at about 90 miles per hour, v = 40 m/s, on solid rock ground. we now put him into space. when he throws the ball, which weighs mb = 0.15 kg moves away from himat the same speed. how long does it take the ball thrown in space to travel the 30 meters to the batter? he weighs mp = 100kg

What are the similarities & differences between a thermistor and a light dependent resistor in physics?

Should we celebrate the voyages of zheng he mini q answer key