Answer:
Explanation:
Speed = distance / time
Velocity = displacement / time
So ,
Speed = 50 km / 0.5 hr = 100 km/h
Velocity = 40 km / 0.5hr = 80 km/h
Answer: The copper wiring most likely caused the mini-refrigerator fire.
Explanation: A mini-refrigerator may have one or more evaporator fan motors. These motors have copper wiring. In some situation these copper wires gets overheated. It may result to the firing of the mini-refrigerator.
Therefore, the mini-refrigerator fire was most likely caused by copper wiring.
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
