Answer:
Coefficient of kinetic friction = 0.146
Explanation:
Given:
Mass of sled (m) = 18 kg
Horizontal force (F) = 30 N
FInal speed (v) = 2 m/s
Distance (s) = 8.5 m
Find:
Coefficient of kinetic friction.
Computation:
Initial speed (u) = 0 m/s
v² - u² = 2as
2(8.5)a = 2² - 0²
a = 0.2352 m/s²
Nweton's law of :
F (net) = ma
30N - μf = 18 (0.2352)
30 - 4.2336 = μ(mg)
25.7664 = μ(18)(9.8)
μ = 0.146
Coefficient of kinetic friction = 0.146
I can answer number 2 for you only. I don’t know if it’s correct or not this is what I THINK it is:
2. Burning fossil fuels creates greenhouse gases, which changes the climate.
Ps. Climate is long term weather. Aka weather over a long period of time.
I am not sure how you want me to answer this, but yes, gas can go from being a gas to a liquid when the right temp and pressure is applied.
Note:
1 A (armstrong) = 10⁻¹⁰ m
1 nm (nanometer) = 10⁻⁹ m
Given:
Radius of a krypton atom = 1.9 A = 1.9 x 10⁻¹⁰ m
Part (a)

Answer: 0.019 nm
Part (b)
The diameter of a krypton atom = 2*1.9A = 3.8 A = 3.8 x 10⁻¹⁰ m.
The number of krypton atoms within a length of 1.0 mm is

Answer: About 2.632 x 10⁶ atoms
Part (c)
The radius of a krypton atom is
1.9 A = (1.9 x 10⁻¹⁰ m)*(10² cm/m) = 1.9 x 10⁻⁸ cm
The volume of a krypton atm is

Answer: 2.873 x 10⁻²³ cm³