A boat heads north at 30 mph while a steamer heads east at 40 mph at the same time. When is the distance between them 50 mi? Ans
1 answer:
Answer:
1 hour
Explanation:
Speed of the first boat = 30 mph
Speed of the second = 40 mph
The boats will cover different distances but the time taken will be the same.
Time taken by the boats = t
Distance = Speed × Time
Distance covered by the first boat = 30t
Distance covered by the second boat = 40t
Distance between the boats = 50 mi
From the Pythagoras theorem
Time taken by the boats when they are 50 mi away is 1 hour
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We can calculate the aceleration, applicating the formula:
Like you see, the final velocity will be zero, so:
Like you see, the aceleration applicate by superman is of <u>-10 m/s^2.</u>
If the aceleration is negattive, means the velocity will decrease.
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For calculate the force applicate for superman, lets applicate the second law of Newton:
Lets replace and resolve it:
F = 8x10^3 kg * (-10 m/s^2)
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Answer:
1. a
2. b
3. b
Explanation:
1.
Resistance is the property of a conductor to offer resistance to the flow of current. The lower the resistance better is the conductivity of wire.
We know that the resistance of a wire depends on several factor which are inter-connected by an equation as:
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As the collision between the electrons and protons increases the speed of the flow of charges will decrease because the opposite charges attract each other and as we know that electrical current is the rate of flow of charge.
3.
Heating up of wire due to sunlight will cause lattice vibration in the conductor and will obstruct the movement of the charges which build up electric current, hence increasing the resistance of conductivity.