Chapter 5 Applications of Newton's law Sec 5-1 Force Laws Sec 5-2 Tension and normal forces Sec, 5-3 Friction forces Sec. 5-4 The dynamics of uniform circular motion x Sec. 5-5 Time-dependent force Sec. 5-6 Noninertial frames and pseudoforces Sec 5-7 Limitations of Newton's law
Chapter 5 Applications of Newton’s Law Sec. 5-1 Force Laws Sec. 5-2 Tension and normal forces Sec. 5-3 Friction forces Sec. 5-4 The dynamics of uniform circular motion Sec. 5-5 Time-dependent force Sec. 5-6 Noninertial frames and pseudoforces Sec. 5-7 Limitations of Newton’s law ★ ★ ★
Sec. 5-1 Force Laws Physicists have traditionally identified four basic forces (1)tne cirayiracional force (2)the elecirormacnetic force (3)the weak nuclear force, which causes certain radioactive decay processes and certain reactions among the fundamental particles (4)the strong force, which operates among the fundamental particles and is responsible for binding the nucleus together
Sec. 5-1 Force Laws Physicists have traditionally identified four basic forces: (1) the gravitational force (2) the electromagnetic force (3) the weak nuclear force, which causes certain radioactive decay processes and certain reactions among the fundamental particles. (4) the strong force, which operates among the fundamental particles and is responsible for binding the nucleus together
Two priors in Typical nucleus, for example, the relative strength of these forces would be strong(relative strength =1) electromagnetic( 10 weak(10); gravitational (103) In fact, everything we study about ordinary mechanical systems involves only two force cIralviry and elecirorgacnetisrn Tension forces Normal forces Friction forces
Two protons in typical nucleus, for example, the relative strength of these forces would be: strong (relative strength = ); electromagnetic( ); weak ( ); gravitational ( ). 2 10 − 38 10 9 − 10− 1 In fact, everything we study about ordinary mechanical systems involves only two force: gravity and electromagnetism. Tension forces Friction forces Normal forces
Sec. 5-2 Tension and normal forces (张力与压力 )Tension force(such as in a stretched rope or string), arises because each small element of the string pulls on the element next to it If the mass of the rope is negligible, the values of the force exerted on the two ends of the rope must be nearly equal to each other
Sec. 5-2 Tension and normal forces (张力与压力) (1) Tension force (such as in a stretched rope or string), arises because each small element of the string pulls on the element next to it. m If the mass of the rope is negligible, the values of the force exerted on the two ends of the rope must be nearly equal to each other
(2)Normal force: Just like tension force the normal force is also contact force Both tension and normal forces originate with the atoms of each body ---each atom exerts a force on its neighbor. They belong to electromagnetic forces
(2) Normal force : Just like tension force, the normal force is also contact force. Both tension and normal forces originate with the atoms of each body --- each atom exerts a force on its neighbor. They belong to electromagnetic forces. N' − N