And.. where is the rest of the question?
It takes 392 joules of work to lift it.
It has 392 joules of gravitational potential energy up there.
Answer:
50.2 m
Explanation:
We can solve the problem by using the following SUVAT equation for the vertical position of the rock:
where
h is the initial height (the depth of the canyon), taking the bottom of the canyon as reference position
u = 0 is the initial velocity of the rock
t is the time
is the acceleration of gravity
When the rock reaches the bottom, t = 3.2 s and y = 0. Substituting these numbers and solving for h, we find the depth of the canyon:
Okay, so the density of water is 1g/cm3. In order for the cube to float, it has to be less than 1, and it will sink if it is more than 1 g/cm3. Use a triple beam balance to weigh the cube, looking at the metric ruler on the balance. Then, if the cube's density is more than 1, then you know it will float. If the density is less than 1, you know it will sink.
hope this helps, and I didn't know how to use the word "metric ruler"