Answer:
α = 2,857 10⁻⁵ ºC⁻¹
Explanation:
The thermal expansion of materials is described by the expression
ΔL = α Lo ΔT
α = 
in the case of the bar the expansion is
ΔL = L_f - L₀
ΔL= 1.002 -1
ΔL = 0.002 m
the temperature variation is
ΔT = 100 - 30
ΔT = 70º C
we calculate
α = 0.002 / 1 70
α = 2,857 10⁻⁵ ºC⁻¹
<h3><u>Given</u> :</h3>
Current flow light bulb = 2.5
Resistance of light bulb = 3.6Ω
<h3><u>To Find </u>:</h3>
We have to find voltage of battery
<h3><u>Solution</u> :</h3>
➠ As per ohm's law, current flow through a conductor is directly proportional to the applied potential difference.
➝ V ∝ I
➝ <u>V = I × R</u>
Where, R is the resistance of conductor.
⇒ V = I × R
⇒ V = 2.5 × 3.6
⇒ <u>V = 9 volt</u>
Answer:
A. Materials with a low index of refraction cause light to refract very little.
Given parameters:
First velocity = 2.50m/s
Time of travel = 3s
Second velocity = 1.50m/s
Unknown:
The displacement during the first interval = ?
Velocity is the displacement of a body with time. Displacement is a distance move in a specific direction by a body.
Velocity = 
So;
Displacement = Velocity x Time taken
Now input the parameter for the first velocity and time of travel;
Displacement = 2.5 x 3 = 7.5m
The displacement id 7.5m