A 75-N object is pulled on a horizontal surface by a horizontal pull of 50 N to the right. The friction force exerted on this object is 30 N to the left. What is the acceleration of the object?
A) 0.27 m/s2
B) 1.1 m/s2
C) 2.6 m/s2
D) 11 m/s2
Question 2
Which one of the following does not contribute to the problem of greenhouse-effect heating of the atmosphere?
A) automobile engines
B) wood stoves
C) nuclear power plants
D) coal-burning power plants
E) Actually, all of the above contribute to the problem.