Answer:
1.87 A
Explanation:
τ = mean time between collisions for electrons = 2.5 x 10⁻¹⁴ s
d = diameter of copper wire = 2 mm = 2 x 10⁻³ m
Area of cross-section of copper wire is given as
A = (0.25) πd²
A = (0.25) (3.14) (2 x 10⁻³)²
A = 3.14 x 10⁻⁶ m²
E = magnitude of electric field = 0.01 V/m
e = magnitude of charge on electron = 1.6 x 10⁻¹⁹ C
m = mass of electron = 9.1 x 10⁻³¹ kg
n = number density of free electrons in copper = 8.47 x 10²² cm⁻³ = 8.47 x 10²⁸ m⁻³
= magnitude of current
magnitude of current is given as
= 1.87 A
Answer:
Friction can be minimized by using lubricants like oil and grease and by using ball bearing between machine parts. A substance that is introduced between two surfaces in contact, to reduce friction, is called a lubricant. Fluid friction can be minimized by giving suitable shapes to the objects moving in the fluids.
Explanation:
hope it helps
Work done is by the change in the potential energy of the system. The work done by gravity is 924.63 J.
<h3>
What is the Kinetic Energy?</h3>
- Potential energy in physics is the energy that an item retains as a result of its position in relation to other objects, internal tensions, electric charge, or other elements.
- The gravitational potential energy of an object, which is based on its mass and distance from another object's center of mass, the elastic potential energy of an extended spring, and the electric potential energy of an electric charge in an electric field are examples of common types of potential energy. The joule, denoted by the letter J, is the energy unit in the International System of Units (SI).
Solution:
mass = 5.10 kg
height = 18.5 mm
We know that work done by the gravity on the watermelon is the change in the potential energy of the watermelon, therefore,
Work done due to gravity = change in the potential energy of the system
W = 
W = mg (h₀ - h₁)
W = 5.10 × 9.8 × 18.5
W = 924.63 J
know more about potential energy brainly.com/question/24284560
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Answer: They behave the same because, according to the principle of equivalence, the laws of physics work the same in all frames of reference.
Explanation:
According to the equivalence principle postulated by Einstein's Theory of General Relativity, acceleration in space and gravity on Earth have the same effects on objects.
To understand it better, regarding to the equivalence principle, Einstein formulated the following:
A gravitational force and an acceleration in the opposite direction are equivalent, both have indistinguishable effects. Because the laws of physics must be accomplished in all frames of reference.
Hence, according to general relativity, gravitational force and acceleration in the opposite direction (an object in free fall, for example) have the same effect. This makes sense if we deal with gravity not as a mysterious atractive force but as a geometric effect of matter on spacetime that causes its deformation.
Answer:
Work done by a tug boat, W = 1.735 x 10⁸ J
Explanation:
Given,
The of each tugboat, F = 1.5 x 10⁶ N
The angle of each tugboat forms with the resultant force, θ = 19°
The displacement of the supertanker, s = 710 m
The individual tugboat will be responsible for the displacement, d = 710/2
= 355 m
The displacement component in each tugboat direction = 355 · sin θ meter
Therefore, the work done by each tugboat is
W = F x S joules
Substituting the values in the above equation
W = 1.5 x 10⁶ x 355 · sin θ
= 1.735 x 10⁸ J
Hence, the work done by each tugboat is, W = 1.735 x 10⁸ J
