Answer:
The difference in the length of the bridge is 0.42 m.
Explanation:
Given that,
Length = 1000 m
Winter temperature = 0°C
Summer temperature = 40°C
Coefficient of thermal expansion 
We need to calculate the difference in the length of the bridge
Using formula of the difference in the length

Where,
= temperature difference
=Coefficient of thermal expansion
L= length
Put the value into the formula


Hence, The difference in the length of the bridge is 0.42 m.
Answer:
F1= 588 N
F2= 784 N
Explanation:
Please see the attached file.
A ball hit by a man is stronger than a ball hit by a man because the man uses more force when hitting the ball than the boy does.
B.The water molecules in the black can had the largest increase in average kinetic energy.
<u>Explanation:</u>
Here, black painted can absorbs more heat than the other color painted cans.
Black color absorbs all the heat and didn't reflect anything back, so it absorbs the most heat.
White color reflects all the heat, so heat absorbed by the white can is least.
When the black can absorbs heat then the water molecules in the can gets its maximum amount of kinetic energy so that the water molecules in the can collide with each other and also along with the walls of the can here, and so the average kinetic energy increases.