If the cross-section of a wire of fixed length is doubled, the resistance of that wire change into doubled.We know that <span>the total </span>length<span> of the wires will </span>affect<span> the amount of </span>resistance. <span> The longer the wire, the more </span>resistance<span> that there will be so the answer is doubled.</span>
Acceleration is measured in meters per second square.
Answer:
354.72 m/s
Explanation:
= mass of lead bullet
= specific heat of lead = 128 J/(kg °C)
= Latent heat of fusion of lead = 24500 J/kg
= initial temperature = 27.4 °C
= final temperature = melting point of lead = 327.5 °C
= Speed of lead bullet
Using conservation of energy
Kinetic energy of bullet = Heat required for change of temperature + Heat of melting
Answer:
D. Friction and air resistance created heat on his trip up the hill.
Explanation:
Energy transformation from one form to another is not 100% efficient. This is the postulate of the first law of thermodynamics.
Most of the energy transformation is not purely 100%.
When energy is transformed, some are usually wasted.
- In this case, in moving from bottom up, Superman produced some heat and encountered air resistance.
- To reach the top, he must have overcome the resistance and produce enough heat to power him through.
- This reduces the amount of potential energy that should have been the same as the kinetic energy down below.
Answer:
299.88 kgm²/s
499.758 kgm²/s
Explanation:
R = Radius of merry-go-round = 1.63 m
I = Moment of inertia = 196 kgm²
= Initial angular velocity = 1.53 rad/s
m = Mass of person = 73 kg
v = Velocity = 4.2 m/s
Initial angular momentum is given by
The initial angular momentum of the merry-go-round is 299.88 kgm²/s
Angular momentum is given by
The angular momentum of the person 2 meters before she jumps on the merry-go-round is 499.758 kgm²/s
