What is the mass of a steel ball, plastic ball, and a golf ball?

An object moves from position +34m to the position -15m in 15 seconds. what is the total displacement? what is the total velocity?

A90db sound wave strikes an eardrum whose area is 5.0×10^-5m^2. how much energy is absorbed by the eardrum per second

1. what is the si unit of emf? 2.a complete series circuit consists of a 12.0 v battery, a 4.70 ω resistor, and a switch in the closed position. the internal resistance of the battery is 0.30 ω. what does an ideal voltmeter read when placed across the resistor?