Answer:
1) D, 2) D, 3) B, 4) B, 5) C
Explanation:
You are asked to select the correct answer
1) The conservation of energy is one of the most important principles of physics that allows solving countless problems in life.
the correct answer is D
2) when a body falls, the gravitational potential energy is transformed into kinetic energy and both are transformed into thermal energy
the correct answer is D
3) When the gravitational potential energy is maximum, the kinetic energy is minimum and when the kinetic energy is maximum, the gravitational energy is minimum.
Correct answer B
4) speed is defined by
v = x / t
so the correct answer is B in the SI system
5) when we repeat a measurement several times, the random or statistical errors decrease, therefore the confidence of the measurement increases.
The correct answer is C
A) Vector A
The x-component of a vector can be found by using the formula
where
v is the magnitude of the vector
is the angle between the x-axis and the direction of the vector
- Vector A has a magnitude of 50 units along the positive x-direction, so 
. So its x-component is
- Vector B has a magnitude of 120 units and the direction is 
(negative since it is below the x-axis), so the x-component is
So, vector A has the greater x component.
B) Vector B
Instead, the y-component of a vector can be found by using the formula
Here we have
- Vector B has a magnitude of 50 units along the positive x-direction, so . So its y-component is
- Vector B has a magnitude of 120 units and the direction is , so the y-component is
where the negative sign means the direction is along negative y:
So, vector B has the greater y component.
The answer would be Exosphere because, there are 3 main regions that circulate oxygen through the Earths system, which are the Biosphere, Atmosphere, and the Lithosphere.
Answer:
100 m
Explanation:
From the question,
R = Lρ/A.................... Equation 1
Where R = resistance of the wire, L = length of the wire, ρ = resistivity of the wire, A = cross sectional area of the wire.
But,
A = πr².................... Equation 2
Where r = radius of the wire.
Substitute equation 2 into equation 1
R = Lρ/πr²
Make L the subject of the equation
L = Rπr²/ρ...................... Equation 3
Given: R = 40 Ω, r = 5×10⁻⁴ m, ρ = 3.14×10⁻⁷ Ωm
Constant: π = 3.14
Substitute these values into equation 3
L = [40×3.14×( 5×10⁻⁴)²]/ (3.14×10⁻⁷)
L = 40×3.14×25×10⁻⁸/(3.14×10⁻⁷)
L = 100 m
Hence the length of the wire is 100 m
