PHYSICS 1E03 Lecture 5: Lecture 5 Recap

A 100-W resistor, an 800-mH inductor and a 10.0-mF capacitor areconnected in series across a 60.0-Hz 120-V (peak) ac source. Theimpedance of this circuit is approximately

a. 107 W
b. 265 W
c. 100 W
d. 377 W

An object of weight W is in free-fall close to the surface ofearth. What is the force that the object exerts on Earth?

A) a force greater than W

B) A force less than W

c) a force = to W

d) no force at all

A crate of weight W is being pushed across a horizontal surface bya force directed at an angle of 20 degrees below the horizontal.What is the magnitude of the normal force on the crate?
a) it is less than W
b) it equals W
c) it is more than W
d) none of the above since the coefficient of kinetic friction isnot given