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.
The formula for average speed is S=D/T
1. S=72m/37s
Divide
S= 1.94
Kira's average speed is 1.94m/s.
2. S=7.5km / 1.5h
S=5
Your average speed is 5km/h
3. S=1260km/3.5h
S=360
The airplanes average speed is 360km/h
Neutral - they have mass but no charge
(1) Speed is the ratio of the total distance covered by the object and the total time it takes for him to finish it.
Speed = distance / time
In this item, we are given that the distance is 20 kilometers and that the time it takes for the trip is 2 hours. Substituting the known values,
Speed = 20 kilometers / 2 hours
speed = 20 km/h
(2) Velocity on the other hand takes into account the displacement of the object from his original position. It is assumed that Jeremie was basically back to his original position after two hours. Hence, the velocity is equal to zero.
