The answer to this question would be true

**Answer:**

Average speed is 60 km/hr whereas average velocity is 0 km/ hr.

**Explanation:**

The average speed of the boat is 60 km/ hr while on the other hand, the average velocity of the boat is 0 km/ hr because average speed is the total distance covered by the boat in total time and average velocity is the displacement covered by the boat in total time. The total distance covered by the boat is 60 km and the total time is 60 minutes which is equals to one hour so the answer is 60 km/hr whereas the displacement is the shortest distance between initial and final position which is 0 in this case so 0 divided by 60 minutes or one hour is also 0.

**Answer:**

**Explanation:**

Given

Ball of mass m

maximum Bearable Tension in string is F

Let length of the cord be L m and moving at a speed of v m/s

Here Tension will Provide Centripetal Force

T=Centripetal Force

**Answer:**

0.012-m

**Explanation:**

∆L = α × Lo × (T-To)

α is the coefficient of linear expansion = 12 × 10-6 K-1

Lo = Initial length = 25-m

∆L = Change in length

(T-To) = 40 K

∆L = 12 × 10-6 × 25 × 40

∆L = 0.012-m