Answer:
The increase in the gravitational potential energy is 29.93 joules.
Explanation:
Given that,
Mass of the box, m = 2.35 kg
It is lifted from the floor to a tabletop 1.30 m above the floor, h = 1.3 m
We need to find the increase the gravitational potential energy. Initial it will placed at ground i.e. its initial gravitational potential is equal to 0. The increase in the gravitational potential energy is given by :

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U = 29.93 Joules
So, the increase in the gravitational potential energy is 29.93 joules. Hence, this is the required solution.
In order to answer this, we will set up a simple ratio as such:
1 calorie = 4.184 joules
1 kilocalorie = 1000 calories
1 kilocalorie = 4,184 joules
250 kilocalories = x joules
Cross multiplying the second and third equations, we get:
x joules = 4,184 * 250
250 kilocalories are equivalent to 1,046 kJ
Answer:
A friend snorkeling just below the surface of the water along the same shore will detect the sound first.
Explanation:
- The speed of sound in water medium is faster than that through the air.
- Sound propagates through the medium by transferring through the molecules on it. Water has more closely packed molecules due to which the speed is faster.
- In fact, the sound's speed in water is almost four times faster than that in the air.
- So the guy in the water surface gets to hear sound faster than the one in sore.