1) which of the following explains why a bicycle uses a gear?

a.)the gear increases the effort force needed.
b.)the gear increases resistance force.
c.)the gear decreases effort force.
d.)the gear decreases resistance force.

2) which of the following is a compound machine?

a.)a screw being screwed into a piece of wood
b.)a can opener
c.)a crowbar
d.)a wheel and axle

Which of the following describe possible scenarios? a) an object has zero instantaneous velocity and non-zero acceleration. b) an object has negative acceleration and is speeding up. c) an object has positive acceleration and constant velocity. d) an object has positive velocity and zero acceleration. e) an object has increasing positive position and negative velocity. f) an object has decreasing positive position and negative acceleration.