Because of their gravitational pull. Thats how earth has a moon it pulled it into it's gravitational pull. That's why it does a circular rotation around the earth.
Answer:
D) Joe need to walk 481 m in a direction 40.9° north of east
Explanation:
Given:
1. Walk 300 m north
2. Walk 400 m northwest
3. Walk 700 m east-southeast and the treasure is buried there
Taking north as positive y axis and east as positive x axis.
Resolving their positions into x and y vector components.
1. d1 = 300j
2. d2 = -400cos45i + 400sin45j
3 d3 = 700cos22.5i - 700sin22.5j
Resultant position.
d = d1+d2+d3
d = (-400cos45 + 700cos22.5)i + (300+400sin45-700sin22.5)j
d = (363.873)i + (314.964)j
D = √( (363.873)^2 + (314.964)^2)
D =481.25m ~= 481m
Angle = taninverse (314.964/363.873)
Angle = 40.9°
Since the x and y components are both positive, it implies that their position is north of east
Therefore, Joe need to walk 481 m in a direction 40.9° north of east
Incomplete question as the charge density is missing so I assume charge density of 3.90×10^−12 C/m².The complete one is here.
An electron is released from rest at a distance of 0 m from a large insulating sheet of charge that has uniform surface charge density 3.90×10^−12 C/m² . How much work is done on the electron by the electric field of the sheet as the electron moves from its initial position to a point 3.00×10−2 m from the sheet?
Answer:
Work=1.06×10⁻²¹J
Explanation:
Given Data
Permittivity of free space ε₀=8.85×10⁻¹²c²/N.m²
Charge density σ=3.90×10⁻¹² C/m²
The electron moves a distance d=3.00×10⁻²m
Electron charge e=-1.6×10⁻¹⁹C
To find
Work done
Solution
The electric field due is sheet is given as
E=σ/2ε₀
Now we need to find force on electron
Now for Work done on the electron
It must be noted that during an elastic collision both the momentum and kinetic energy are conserved. For the kinetic energy, it can be solved through the equation,
KE = 0.5mv²
Equating the kinetic energies before and after collision,
0.5(60)(8 m/s)² = (0.5)(60)(x²) + (0.5)(0.45)(35 m/s)²
The value of x from the equation is approximately 7.40 m/s
Frictional force
Explanation:
Frictional force is a force that opposes the motion between two surfaces that are in contact with one another.
Frictional force opposes motion and it is directed opposite the direction of motion.
There is also frictional force between liquids too.
- Enough force must be supplied in order to overcome this frictional force so as to make a body move.
- In humans, motion wouldn't be possible without the frictional force.
learn more:
Friction brainly.com/question/7174363
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