The time elapsed when the vehicles are closest to each other is 20 min.
The given parameters:
The time elapsed when the cars are close to each other is calculated by applying the principles of relative speed.
Thus, the time elapsed when the vehicles are closest to each other is 20 min.
Learn more about relative velocity here: brainly.com/question/24430414
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