Is the use of a toaster 100% efficient? why or why not

Three point charges, two positive and one negative, each having a magnitude of 20 μc are placed at the vertices of an equilateral triangle (30 cm on a side). what is the magnitude of the electrostatic force on the negative charge

Achild throws a ball with an initial speed of 8.00 m/s at an angle of 40.0° above the horizontal. the ball leaves her hand 1.00 m above the ground. how long is the ball in flight before it hits the ground?

Amarble, a bowling ball, a basketball, and a baseball are rolling across the floor at 10 m/s. which one has the greatest kinetic energy? the marble the bowling ball the basketball the baseball