Which of these is an example of overcoming static friction? A. Speeding up on a bike
B. Starting to pedal a bike that is stationary
C. Slowing down on a bike
D. Trying to stop a bike while pedaling

Option B. is the best choice.

Explanation:

Static friction is a force that keeps an object at rest. It must be overcome to start moving the object. Once an object is in motion, it experiences kinetic friction.

B. Starting to pedal a bike that is stationary

Best Regards!

when heated, the valance electrons increased their speed and transferred the heat from electron to electron.   i just took the test.

the minimum constant speed at which she can catch the train is 2.7 m/s

given:

acceleration = 0.6

time = 4.5 s

to find:

velocity = ?

formula used:

from 1st kinematic equation we get,

v = u + at

u = initial speed of train = 0 m/s

v = final speed of the train

a = acceleration of the train

t = time

solution:

from 1st kinematic equation we get,

v = u + at

u = initial speed of train = 0 m/s

v = final speed of the train

a = acceleration of the train

t = time

v = 0 + (0.6 × 4.5)

v = 2.7 m/s

the minimum constant speed at which she can catch the train is 2.7 m/s