Which of the following is a way the atmosphere is affected by pollution?
a emissions from cars
b. toxic runoff from farms
c. dumping trash on roadsides
d. production of oxygen by trees

Matt is driving down 7th street. he drives 150 meters in 18 seconds. assuming he does not speed up or slow down, what is his speed?

The passing of heat through a material while the material itself stays in place. a. radiation b. conduction c. convection

Three different objects, all with different masses, are initially at rest at the bottom of a set of steps. each step is of uniform height . the mass of each object is a multiple of the base mass : object 1 has mass 4..00m , object 2 has mass 1..96m , and object 3 has mass . when the objects are at the bottom of the steps, define the total gravitational potential energy of the three-object system to be zero. if the objects are then relocated as shown, what is the new total potential energy of the system? each answer requires the numerical coefficient to an algebraic expression. each algebraic expression is given using some combination of the variables , , and , where is the acceleration due to gravity. enter only the numerical coefficient. (example: if the answer is 1..23mgd , just enter 1.23)