8 . True or false: In a uniform electric field pointing to the right, a negatively charged particle will move
to the left. If true, justify with an equation; if false, explain the flaw in reasoning.
9 . Which is a vector and which is a scalar: electric field and electric potential?10 . Fill in the blank with either “parallel” or “series”:
a. Voltage across resistors in ______ must be the same for each.
b. Current through resistors in ______ must be the same for each.
c. Voltage across capacitors in ______ must be the same for each.
d. Charge stored on capacitors in ______ must be the same for each.11 . A uniform electric field acts to the right. In which direction will each of these particles accelerate?
a. proton
b. positron (same mass as electron, but opposite charge)
c. neutron
d. anti-proton (same mass as proton, but opposite charge)12 . A uniform magnetic field acts to the right. In which direction will each of these particles accelerate,
assuming they enter the field moving toward the top of the page?
a. proton
b. positron (same mass as electron, but opposite charge)
c. neutron
d. anti-proton (same mass as proton, but opposite charge)
13 . How do you find the potential energy of an electric charge?
Answers to Mechanics Quiz
1 . Weight is mg . So, mass is weight divided by g , which would be 100 N/(10 N/kg) = 10 kg.
2 . PE = mgh , gravitational potential energy;
PE = ½kx 2 , potential energy of a spring.
3 . i. mg sin θ is parallel to the incline.
ii. mg cos θ is perpendicular to the incline.
4 . The definition of work is work = force times parallel displacement. The work-energy principle states
that net work = change in kinetic energy.
5 . vectors: acceleration, force, momentum, velocity, displacement
scalars: speed, work, mass, kinetic energy
6 . Only forces acting on an object and that have a single, specific source can go on free-body diagrams.
Some of the things that cannot go on a free-body diagram but that students often put there by mistake:7 . Impulse is force times time interval, and also change in momentum. Impulse has units either of