Because the plate doesn't have water, and it's water which is heated by the microwave
Answer:
The width of the slit is 0.167 mm
Explanation:
Wavelength of light, 
Distance from screen to slit, D = 88.5 cm = 0.885 m
The distance on the screen between the fifth order minimum and the central maximum is 1.61 cm, y = 1.61 cm = 0.0161 m
We need to find the width of the slit. The formula for the distance on the screen between the fifth order minimum and the central maximum is :

where
a = width of the slit


a = 0.000167 m

a = 0.167 mm
So, the width of the slit is 0.167 mm. Hence, this is the required solution.
The answer is:
71.6 <span>°F</span>
Force=mass x acceleration
f= 0.5 x40
f=20N