Answer:
2.17 Mpa
Explanation:
The location of neutral axis from the top will be
Moment of inertia from neutral axis will be given by 
Therefore, moment of inertia will be
![\frac {240\times 25^{3}}{12}+(240\times 25)\times (56.25-25/2)^{2}+2\times [\frac {20\times 150^{3}}{12}+(20\times 150)\times ((25+150/2)-56.25)^{2}]=34.5313\times 10^{6} mm^{4}}](https://tex.z-dn.net/?f=%5Cfrac%20%7B240%5Ctimes%2025%5E%7B3%7D%7D%7B12%7D%2B%28240%5Ctimes%2025%29%5Ctimes%20%2856.25-25%2F2%29%5E%7B2%7D%2B2%5Ctimes%20%5B%5Cfrac%20%7B20%5Ctimes%20150%5E%7B3%7D%7D%7B12%7D%2B%2820%5Ctimes%20150%29%5Ctimes%20%28%2825%2B150%2F2%29-56.25%29%5E%7B2%7D%5D%3D34.5313%5Ctimes%2010%5E%7B6%7D%20mm%5E%7B4%7D%7D)
Bending stress at top= 
Bending stress at bottom=
Mpa
Comparing the two stresses, the maximum stress occurs at the bottom and is 2.17 Mpa
It’s true the acceleration of falling objects on earth due to gravity is 98ms2
Answer:2t
Explanation:
Given
Jason throwing watermelon at speed v and it spend t time in air
time to reach max height
0=v-gt'
and time to reach bottom is also t'
t=2t'
For guy throws his watermelon at speed 2v
So total time in air will be
t''=2t
Answer:
Explanation:
ignoring air resistance, the kinetic energy at water impact will equal the potential energy converted
½mv² = mgh
v = √(2gh)
v = √(2(9.81)2.1) = 6.4188... m/s
after impact, an impulse will result in a change of momentum.
There is a downward impulse due to gravity equal to the weight of the stone and an upward average force due to water resistance and buoyancy force.
FΔt = mΔv
(F - mg)Δt = m(vf - vi)
(F - mg) = m(vf - vi)/Δt
F = m(vf - vi)/Δt + mg
F = m((vf - vi)/Δt + g)
F = 1.05(((½(-6.4188) - -6.4188)/ 1.83) + 9.81)
F = 12.14198...
F = 12.1 N
