Answer:
0.75
Explanation:
Since the static frictional force is the maximum force applied just before sliding, our frictional force, F is 300 N.
Since F = μN where μ = coefficient of static friction and N = normal force = 400 N (which is the downward force applied against the surface).
So, μ = F/N
= 300 N/400 N
= 3/4
= 0.75
So, the coefficient of static friction μ = 0.75
Answer:
Explanation:
Using the atomic mass of pluonium atoms (244 g/mol), you can calculate the number of atoms in 47.0 g. Then, knowing that each plutonium atom has 96 protons, you calculate the number of protons in the 47.0 g sample. Finally, using the positive charge of one proton, you calculate the total positive charge in the 47.0 g of plutonium.
<u>1. Number of atoms of plutonium in 47.0 g</u>
- Number of moles = mass / atomic mass = 47.0 g / 244 = 0.1926 moles
- Number of atoms = number of moles × 6.022 × 10²³ atoms/mol
- Number of atoms = 0.1926 mol × 6.022 × 10²³ atoms/mol = 1.15998×10²³ atoms
<u>2. Number of protons</u>
- Number of protons = 1.15998×10²³ atoms × 96 protons/atom = 1.11385×10²⁵ protons
<u>3. Charge</u>
<u />
- Charge = charge of one proton × number of protons
- Charge = 1.602×10⁻¹⁹ C/proton × 1.11385×10²⁵ protons = 1.78×10⁶C
Answer: work = 1,305kJ
Explanation:
angle= 30°
force= 1,500N
distance= 1,000m
The formula for work is : Work= force x distance, however there is an angle of 30° between the direction of force applied and the direction of motion, therefore force must be decomposed to its value on the horizontal axis which is the direction of motion by using the cosine of the very angle.
W= F×cos(α)×D
W= 1,500×cos (30)×1,000
W= 1,305kJ ( kilojoules)
Given:
mass: 100 kg
height: 500 m
1 kJ = 1000 J
gravity = 9.8 m/s²
velocity before impact: v = √2gh ; v = √2 * 9.8 m/s² * 500 m ; v = 98.99494 m/s
KE = 1/2 m v²
KE = 1/2 * 100 kg * (98.99494 m/s)²
KE = 490,000 J
Pls. see attachment.
