A chair of weight 100 N lies atop a horizontal floor; the floor is not frictionless. You push on the chair with a force of F = 42.0 NN directed at an angle of 34.0∘ below the horizontal and the chair slides along the floor. Using Newton's laws, calculate , the magnitude of the normal force that the floor exerts on the chair.

Car batteries are often rated in amp-hours. this rating indicates the quantity of charge that can pass through the battery before the battery's chemical energy must be restored by the car's generator or some other source. the amp-hour unit is convenient for simple calculations. for example, a 60-amp-hour battery can supply a current of 1.0 a for 60 h (or 60 a for 1.0 h) before going dead. find the energy stored in the following. (a) a 58 a-h, 10 v car battery(b) a 1.3 a-h, 1.7 v flashlight battery