The way I see it, depending on what the number represents, the number in the decimals spot could mean something significant. hope this helps :)
Answer:
static friction is developed between 2 surfaces in state of rest so i think answer is c.Even though the wheel is in motion, the patch of the tire in contact with the ground is stationary relative to the ground, so it is static rather than kinetic friction.
Answer:
See Below
Explanation:
Mass of child = 21 kg
Mass of bicycle = 5.9 kg
Total mass = 22 + 5.9 = 27.9 kg
Velocity = 4.5 m/s
1) Total momentum of the child and the bike together
= Total mass * Velocity
= 27.9*4.5
= 125.55 kg m per second
2) Momentum of the child
= Mass of child*Velocity
= 21*5.9
= 123.9 kg m per second
3) Momentum of the bike
= Mass of bike*Velocity
= 5.9*4.5
= 26.55 kg m per second
The minimum frequency to extract an electron is D) 
Explanation:
The equation for the photoelectric effect is:
where
(hf) is the energy of the incident photon, where
is the Planck constant
f is the photon frequency
is the work function of the material
is the maximum kinetic energy of the ejected electron
The minimum frequency of the light needed to extract an electron fro mthe surface of the material can be found by requiring that the maximum kinetic energy of the photoelectron is zero:
So we get
For silver, the work function is
Solving for f, we find the minimum frequency:
Learn more about photoelectric effect:
brainly.com/question/10015690
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