Hi there!
We can use the work-energy theorem to solve.
Recall that:
The initial kinetic energy is 0 J because the crate begins from rest, so we can plug in the given values for mass and final velocity:
Now, we can define work:
Now, plug in the values:
Solve for theta:
Distance = speed x time
distance = 116 x 10
distance = 1160 m
Here we know that mass of the person is 90 kg
His weight is given as 30 lbf
so here we can convert it into Newton as we know that
1 lbf = 4.45 N
Now from above conversion
now we can use this to find the gravity at this height
now we know that with height gravity varies as
so above is the height from the surface of earth
The common method would be to use Balance, If you think about it, on other planets, the balance weights change by the same factor as the object you are measuring. Your mass measured with a balance would be the same on the moon as it is on Earth. Weight is a measuring of gravity's effect on something. Mass is another story, it's the amount of matter in an object. Move to another planet and its object's weight will change, however, its mass will remain the same.
The answer is 3 m. This is the area under the graph from t=2 to t=3, using the trapezium rule. 1/2 (2+4) * 1