Answer:

Explanation:
As we know that thermal expansion coefficient of aluminium is given as

now we also know that after thermal expansion the final length is given as

here we know that



now we will have


Answer:
mistakes I guess lol don't take serious
Answer:
V = 6 m/s
Explanation:
Given that,
Initial speed of an object is 20 m/s
Final speed of an object is 10 m/s
Time, t = 5 s
We need to find the average speed of the object during these 5 seconds. Let it is equal to V. Here, time is same. The average speed is given by :

So, the average speed of the object is 6 m/s.