Define simple machine​

How can you increase the strength of an electromagnet?

Consider the following position function. find (a) the velocity and the speed of the object and (b) the acceleration of the object. bold r left parenthesis t right parenthesisr(t)equals=left angle 6 t superscript 4 baseline comma 2 t cubed right angle6t4,2t3 for tgreater than or equals≥0

Explain why electric current cannot exist if a current doesn't have a voltage source.