Either soft or hard but brittle.
The correct statement should be: Descriptive investigations involve collecting data about a system, but not making comparisons.
so i believe the statement above is false
In descriptive investigations, we shall not make any hypothesis for the situation and we just need to fully record all obeservations.
By doing this, we could fully analyze the variables without comparing and manipulating it.
Answer:
a. Both wires have the same resistivity
Explanation:
For the resistance of a wire , following formula holds good .
R = ρ l / S , R is resistance , l is length , S is cross sectional area and ρ is resistivity of the material that the wire is made of. Resistance is dependent on length and cross sectional area but resistivity does not depend upon length or cross sectional area . It only depends upon the type of material.
If we replace copper wire with aluminium wire , then resistivity will change .
Hence , since the wire remains made of copper , resistivity will not change.
Answer:
Explanation:
For a linear elastic material Young's modulus is a constant that is given by:
Here, F is the force exerted on an object under tensio, A is the area of the cross-section perpendicular to the applied force, 
is the amount by which the length of the object changes and 
is the original length of the object. In this case the force is the weight of the mass:
Replacing the given values in Young's modulus formula:
Answer:
5080.86m
Explanation:
We will divide the problem in parts 1 and 2, and write the equation of accelerated motion with those numbers, taking the upwards direction as positive. For the first part, we have:
We must consider that it's launched from the ground (
) and from rest (
), with an upwards acceleration 
that lasts a time t=9.7s.
We calculate then the height achieved in part 1:
And the velocity achieved in part 1:
We do the same for part 2, but now we must consider that the initial height is the one achieved in part 1 (
) and its initial velocity is the one achieved in part 1 (
), now in free fall, which means with a downwards acceleration 
. For the data we have it's faster to use the formula 
, where d will be the displacement, or difference between maximum height and starting height of part 2, and the final velocity at maximum height we know must be 0m/s, so we have:
Then, to get 
, we do:
And we substitute the values:
