Suppose you have a glider and a hanging mass that you wish to know the masses of but you do not have a triple-beam balance available. You set up an experiment like that done in Lab 4: Newton's Second Law, in which a glider moves across an essentially frictionless airtrack, pulled by a light string which passes over a pulley and connects to a hanging mass. You take the following data: H = 75.0 cm t = 1.8 s Where H is the distance the hanging mass falls and t is the time it takes to fall (t has been averaged over five trials). Using methods similar to those in Lab 4, determine which of the following could be the masses of the glider (m1) and the hanging mass (m2).

The illuminance of a surface varies inversely with the square of its distance from the light source. if the illuminance of a surface is 120 lumens per square meter when its distance from a certain light source is 6 meters, by how many meters should the distance of the surface from the source be increased to reduce its illuminance to 30 lumens per square meter?

Learning goal: to understand newton's 1st law. newton's principia states this first law of motion: an object subject to no net force maintains its state of motion, either at rest or at constant speed in a right line. this law may be restated as follows: if the sum of all forces acting on an object is zero, then the acceleration of that object is zero. mathematically this is just a special case of the 2nd law of motion, f⃗ =ma⃗ , when f⃗ =0. when studying newtonian mechanics, it is best to remember the 1st law in two ways: if the net force (i. e., sum of all forces) acting on an object is zero, the object will keep moving with constant velocity (which may be zero). if an object is moving with constant velocity, that is, with zero acceleration, then the net force acting on that object must be zero. complete the following sentences to see if you can apply these ideas. part a if a car is moving to the left with constant velocity, one can conclude that

If a car is traveling on the highway at a constant velocity, the force that pushes the car forward must be a. equal to the weight of the car. b. less than the force of friction exerted upon the car. c. equal to the force of friction exerted upon the car. d. greater than the weight of the car.