Answer:
0.001152m
Explanation:
Linear expansivity of a material is the change in length of the material per unit length per degree rise in temperature. Mathematically,
¢ = ∆L/L1∆°C
¢ is the linear expansivity of the material = 12 x 10⁻⁶ °C⁻¹
Where ∆L is the change in length = L2-L1
L2 is the final length = ?
L1 is the initial length = 12m
∆°C is the change in temperature = °C2 - °C1 = 50-(-30) = 80°C
Substituting this values inside the formula to get the final length L2 after expansion, we have;
12 x 10⁻⁶ °C⁻¹ = L2-12/12×80
12 x 10⁻⁶ °C⁻¹ = L2-12/960
L2-12= 960×12 x 10⁻⁶ °C⁻¹
L2-12 = 0.001152
L2 = 12+0.001152
L2 = 12.001152m
Expansion will be the change in length L2-L1 = 12.001152-12
= 0.001152m
The expansion cracks between the slabs should be 0.001152m wide to prevent buckling
Force = rate of change of momentum = 0.16(38 + 44)/0.002 = 6560 N
Answer:
Red
Explanation:
Red is a colour which has the lowest frequency. Violet has the highest frequency. Frequency has a direct relationship with energy. This means the higher the frequency, the higher the energy. Red has the lowest energy of all the colors too.
The frequency and Energy has an inverse relationship with the wavelength.
However Red has the longest wavelength of about 620 - 780 nanometer.
Suppose rowing speed is V km/s.
So, upstream speed = V-2
Downstream speed = V+ 2
Total time is taken 3 h 20 min to cover up and down journey of 5 km.
So, total time = upstream time + downstream time
and 
, we take only positive velocity.
Thus, the the rowing speed of the crew in still water is 1 km/s.
Not at all. Density on its own is not sufficient
