Ch 04: Intro to Forces (Dynamics)See all chapters
All Chapters
Ch 01: Units & Vectors
Ch 02: 1D Motion (Kinematics)
Ch 03: 2D Motion (Projectile Motion)
Ch 04: Intro to Forces (Dynamics)
Ch 05: Friction, Inclines, Systems
Ch 06: Centripetal Forces & Gravitation
Ch 07: Work & Energy
Ch 08: Conservation of Energy
Ch 09: Momentum & Impulse
Ch 10: Rotational Kinematics
Ch 11: Rotational Inertia & Energy
Ch 12: Torque & Rotational Dynamics
Ch 13: Rotational Equilibrium
Ch 14: Angular Momentum
Ch 15: Periodic Motion (Oscillations)
Ch 16: Waves & Sound
Ch 17: Fluid Mechanics
Ch 18: Heat and Temperature
Ch 19: Kinetic Theory of Ideal Gasses
Ch 20: The First Law of Thermodynamics
Ch 21: The Second Law of Thermodynamics
Ch 22: Electric Force & Field; Gauss' Law
Ch 23: Electric Potential
Ch 24: Capacitors & Dielectrics
Ch 25: Resistors & DC Circuits
Ch 26: Magnetic Fields and Forces
Ch 27: Sources of Magnetic Field
Ch 28: Induction and Inductance
Ch 29: Alternating Current
Ch 30: Electromagnetic Waves
Ch 31: Geometric Optics
Ch 32: Wave Optics
Ch 34: Special Relativity
Ch 35: Particle-Wave Duality
Ch 36: Atomic Structure
Ch 37: Nuclear Physics
Ch 38: Quantum Mechanics

Forces with Multiple Objects

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Concept #1: Forces with Multiple Objects

Practice: A 0.5 kg rope pulls a 15 kg block across a frictionless horizontal surface. If the block moves with 2 m/s2 , how much force pulls the rope forward? (Hint: if the rope used to pull an object is NOT massless, it acts as an additional object).

Practice: Two blocks are initially at rest on a horizontal frictionless surface, as shown. You push on the 4 kg block with a constant horizontal force F. If the contact force between the two blocks is 12 N, calculate the magnitude of force F.

Practice: A 5,000-kg truck carrying a 300-kg crate on its horizontal flatbed comes to a complete stop from +20 m/s in 40 m. What force (use +/- to indicate direction) must the truck apply on the crate, so that it stops without slipping forward?