Answer:
C. Copper
Explanation:
F = Force on string
= Intial length of string
A = Area of string
E = Young's modulus of material
Change in length is given by

It can be seen that the change in length is inversely proportional to the Young's modulus of the material.
Here




So, copper will stretch the least.
Initial velocity u = 40
Angle at launch = 55 degrees
At maximum height v = 0, velocity equation v^2 = u^2 - 2gh,
0 = (40 x sin55)^2 - 2 x 9.81 x h => (40 x 0.819)^2 = 19.62h => h = 32.76^2 /
19.62
Maximum height = 54.7 m
We have v = u - gt => 0 = (40 x sin55) - 9.81 x t => t = 32.76 / 9.81 => t =
3.34 s
Time taken to hit the ground is 2t = 2 x 3.34 = 6.68 s
Distance from castle to trebuchet = utcos55 = 40 x 6.68 x 0.573 = 153.1 m
Answer: C. Magnitude increases by 2
Explanation:
I think the answer is strong force.