It takes 399 newtons to move a 7.2 kg object. What is the acceleration of the object?
1 answer:
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Gravitational force is determined by mass
Answer: Option B
<u>Explanation:</u>
According to Universal law of gravity, the gravitational force is directly proportional to the product of the masses of the objects and inversely proportional to the square of the distance between the objects.
Where,
G – gravitational constant =
= masses of two objects
r – distance between the objects
So, as per this law, the gravitational force is found by mass.
The current flowing in silicon bar is 2.02 10^-12 A.
<u>Explanation:</u>
Length of silicon bar, l = 10 μm = 0.001 cm
Free electron density, Ne = 104 cm^3
Hole density, Nh = 1016 cm^3
μn = 1200 cm^2 / V s
μр = 500 cm^2 / V s
The total current flowing in the bar is the sum of the drift current due to the hole and the electrons.
J = Je + Jh
J = n qE μn + p qE μp
where, n and p are electron and hole densities.
J = Eq (n μn + p μp)
we know that E = V / l
So, J = (V / l) q (n μn + p μp)
J = (1.6 10^-19) / 0.001 (104
1200 + 1016
500)
J = 1012480 10^-16 A / m^2.
or
J = 1.01 10^-9 A / m^2
Current, I = JA
A is the area of bar, A = 20 μm = 0.002 cm
I = 1.01 10^-9
0.002 = 2.02
10^-12
So, the current flowing in silicon bar is 2.02 10^-12 A.
Answer:
T = 17649.03 N = 17.65 KN
Explanation:
The tension in the cable must be equal to the apparent weight of the passenger. For upward acceleration:
where,
T = Tension in cable = ?
= Apparent weight
m = mass = 1603 kg
g = acceleration due to gravity = 9.81 m/s²
a = acceleration of elevator = 1.2 m/s²
Therefore,
<u>T = 17649.03 N = 17.65 KN</u>