click below

click below

Normal Size Small Size show me how

# Physics ch 2_

Question | Answer |
---|---|

What is the SI unit for force? | the Newton (N), or kg*m/s^2 |

What is mass? | a measure of a body’s inertia, which never changes |

What is weight? | a measure of gravitational force on an object’s mass. W = mg |

What is Newton’s first law? | F=ma=0 A body at rest or in mostion with constant velocity remains until a net force acts on it. |

What is Newton’s second law? | sumF = ma m will accelerate when a vector sum of the forces results in a nonzero resultant force vector. |

What is Newton’s third law? | Fb = -Fa For every force exerted by B on A, there is an equal but opposite force of A on B |

What is the equation for the gravitation force F between two objects? | F = Gm1m2 / r^2 |

What is G? | The universal gravitational constant, 6.67 x 10^-11 Nm^2 / kg^2 |

What is translational motion? | An object moving without any rotation about a fixed point in the object |

What is rotational motion? | When a force is applied on an object in a way to cause it to rotate around a fixed pivot point, known as the fulcrum |

What is torque, tau? | the moment of force, which generates the rotational motion; it depends not only on the magnitude of force but also on the angle at which the force is applied and the distance between the fulcrum and the point of force application |

What is the equation for torque? | tau = rF sintheta |

What is uniform circular motion? | when the speed of the moving object is constant |

What is the tangential force in uniform circular motion? | zero, because there is no change in the speed of the object |

What is the centripetal force in uniform circular motion? | It is the resultant force, the radial force and generates centripetal acceleration, keeping the object in its circular pathway |

What equation describes circular motion? | F = mv^2 / r |

What is friction? | A kind of force that works to oppose the movement of objects, almost always forcing objects to slow down |

What are the two kinds of friction? | static and kinetic |

What is static equation and what is its equation? | It is the friction that exists between a stationary object and the surface upon which it rests. 0< fs < MusFn (coeffecient of static friction times the normal force) |

What is kinetic friction? | It exists between a sliding object and the surface over which the object slides |

What is the equation for kinetic friction? | fk = Muk Fn |

What is translational equilibrium? | It exists only when the vector sum of all of the forces acting on an object is zero. The object will have constant speed and direction |

What is rotational equilibrium? | when the vector sum of all torques acting on an object is zero |