In physics and chemistry, the law of conservation of energy states that the total energy of an isolated system remains constant; it is said to be conserved over time. This law means that energy can neither be created nor destroyed; rather, it can only be transformed or transferred from one form to another.
When an elevator is accelerating downward, the normal force is equal to mg-ma (hence you feel a little lighter when accelerating downwards)
Therefore, the upward force of the elevator floor on the person must be less than 750N
Answer : The final temperature is, 
Explanation :
In this problem we assumed that heat given by the hot body is equal to the heat taken by the cold body.
where,
= specific heat of ice = 
= specific heat of water = 
= mass of ice = 50 g
= mass of water = 200 g
= final temperature = ?
= initial temperature of ice = 
= initial temperature of water = 
Now put all the given values in the above formula, we get:
Therefore, the final temperature is,
Answer:
75.645 J
Explanation:
The kinetic energy is related to the mass and velocity by the formula ...
KE = 1/2mv²
For the given mass of 0.045 kg, and velocity of 41 m/s, the kinetic energy is ...
KE = 1/2(0.045 kg)(41 m/s)² = 75.645 J
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The unit of energy, joule, is a derived unit equal to 1 kg·m²/s².
