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According to Newtons 3rd law of Motion, for every action, there is an equal and opposite reaction. So if the boy is pushing forward on a crate with a force of 100 newtons, the crate is pushing back on the boy with a force of 100 newtons. Hope this helps
Answer:
Ratio of resistance of wire with larger diameter to smaller diameter is 4.
Explanation:
Resistance is defined as the property of the material/wire to oppose the flow of current through it.
Resistance (R) of the wire is determine by the relation:
R = (рL)/A
Here р is resistivity of the wire and it depends upon the material of the wire, L is length of the wire and A is the area of the wire.
Area of wire, A = π (d/2)²
Here d is diameter of the wire.
According to the question, let R₁ and R₂ be the resistance of the two copper wires, d₁ and d₂ be there diameters respectively and L and р be the length and resistivity of the two wire respectively. Since, L and р are same foe two wires.
Hence, there ratio of resistance is given by:
=
=
We know that d₂ = 2d₁
= = 4
Answer:
Speed of the ambulance is 32.7 metres per second.
Explanation:
Let the actual frequency of the siren be .
Frequency observed by me when ambulance is approaching = 540 Hz
Frequency observed by me when ambulance is moving away = 446 Hz
Let be the speed of sound and be the speed of ambulance.Then according to Doppler effect:
When source is moving towards observer,frequency observed is given as
= 540 Hz
When source is moving away from observer,frequency observed is given as
= 446 Hz
Taking and solving the above two equations by eliminating ,
we get
Internal energy of the system changes by ΔE = 178 J.
Heat given to the system = Q = +658 J.
According to the first law of thermodynamics,
ΔE = Q + W
178 = 658 + W
∴ W = 178-658 = -480 J
Minus sign indicates that work is done by the system.