Answer:
The anomalous expansion of water is an abnormal property of water whereby it expands instead of contracting when the temperature goes from 4°C to 0°C, and it becomes less dense. The density becomes less and less as it freezes because molecules of water normally form open crystal structures when in solid form.
It depends on how much time 45 j will go, so if you told me that it went through 45 j per minute it will go through for 2 minutes so not efficient unless it went through 45 j per hour then it is efficient.
In 0.25h it will move in 22.5 kilometers.
Answer:
The Y-axis in a Velocity/Time graph is the Velocity.
Explanation:
The speed is the velocity. Like in math, speed(velocity)=distance over time. Where time is the X-axis.
You say to yourself "Self ! Energy can't be created or destroyed.
The skier's kinetic energy at the bottom of the hill is exactly the
potential energy s/he had at the top."
Potential energy at the top = (mass) (gravity) (height)
= (65.8 kg) (9.8 m/s²) (521 m)
= (65.8 x 9.8 x 521) kg-m²/s²
= 335,961.6 joules .
Part-a: No energy is lost on the way down.
Kinetic energy at the bottom = (1/2) (mass) (speed²)
335,961.6 joules = (1/2) (65.8 kg) (speed²)
335,961.6 joules / 32.9 kg = speed²
335,961.6 kg-m²/s² / 32.9 kg = speed²
(335,961.6 / 32.9) m²/s² = speed²
speed = 101 m/s
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Part b: Energy is lost on the way down.
Just subtract the 1.4 x 10⁵ J of energy away from the 335,961.6 J
before you do the Kinetic Energy calculation at the bottom of the hill.
The skier lost that much energy on the way down, by scraping against
snow and air and stuff, so it isn't available to make speed at the bottom.
