<u>Answer
</u>
D. Salt water is denser than freshwater.
<u>Explanation</u>
A boat is able to float on water because it experiences an upthrust upwards.
The magnitude of the upthrust depends on the density of the liquid.
When the liquid is denser the boat will experience a great upthrust as compared to when in a less dense liquid.
If the boat sinks lower in the freshwater than in salty water, then Salt water is more dense than freshwater.
B will be your answer hope this helped
(a) 392 N/m
Hook's law states that:
(1)
where
F is the force exerted on the spring
k is the spring constant
is the stretching/compression of the spring
In this problem:
- The force exerted on the spring is equal to the weight of the block attached to the spring:

- The stretching of the spring is

Solving eq.(1) for k, we find the spring constant:

(b) 17.5 cm
If a block of m = 3.0 kg is attached to the spring, the new force applied is

And so, the stretch of the spring is

And since the initial lenght of the spring is

The final length will be

Power = work/time
= 500/10
= 50J/s or 50 watt
Rocks, earth aging, fossils