Answer:
A- mass and type of material
B- type of material
C- Temperature
Explanation:
thx
Answer:
D. 371 N
Explanation:
Friction force equals normal force times the coefficient of friction:
F = Nμ
Since the ground is level, normal force equals weight:
N = mg
Therefore:
F = mgμ
F = (61 kg) (9.8 m/s²) (0.62)
F = 371 N
Answer:
Explanation:
It is given that,
Radius of the circle,
The area of the circle is given by :
or
As there is no uncertainty given in the radius of the circle. So, the area of the circle is . Hence, this is the required solution.
Answer:
a) 0.15 μC b) 9.4*10¹¹ electrons.
Explanation:
As the total charge must be conserved, the total charge on the spheres, after being brought to contact each other, and then separated, must be equal to the total charge present in the spheres prior to be put in contact:
Q = +8.2μC +9.0 μC +(-7.8 μC) + (-8.8 μC) = +0.6 μC
As the spheres are assumed perfect conductors, as they are identical, once in contact each other, the excess charge spreads evenly on each sphere, so the final charge, on each of them, is just the fourth part of the total charge:
Qs = Qt/4 = 0.6 μC / 4 = 0.15 μC.
b) As the charge has a positive sign, this means that each sphere has a defect of electrons.
In order to know how many electrons are absent in each sphere, we can divide the total charge by the charge of one electron, which is the elementary charge e, as follows:
120/60= 2m per s
220/55= 4m per s
720/80= 9m per s
Fastest run: 3rd run
Speed: 9m per s
Slowest: 1st run
Speed: 2m per s