The causes of acceleration of a system--The first law of motion states that zero total force exists when the system has a constant velocity; a nonzero total force on the system causes its acceleration

The gravitational force 2. Newtons law of universal gravitation

1. The position vector and displacement Let the plane of the two-dimensional motion be the x-y plane of a Cartesian coordinate system

I. Choose the Correct Answer . real engine has an efficiency of33%. The engine has work output of2 4J4 per cycle.how much heat energy is extracted from the high-temperature reservoir per cycle? (D) (A)8J

1. The discovery of electrification OThe phenomenon of electrification Glass rod is rubbed with silk-positive Amber rod is rubbed with fur--negative

Electric Fields 918.1 Conductors in electric field 1. Conductors A conductor is a material in which the electrons at the outer periphery of an atom have no great affinity for any particular individual

I. Choose the Correct Answer 1. Which statement is most correct? (C) (A)Uniform circular motion causes a constant force toward the center. (B)Uniform circular motion is caused by a constant force toward the center

1 Light waves and the coherent condition of waves 1. Light waves Light wave is a small part of the whole electromagnetic wave spectrum. Wavelength (m) 102

I．Choose the Correct Answer 1. An object is moving in a circle at constant speed v. The magnitude of the rate of change of momentum of the object （ C ）

Chapter 13 temperature, heat transfer, and first law of thermodynamics Thermodynamics study the thermal energy (often 10\ -Universe just after beginning called the internal energy) of systems