The number of significant digits of any measurement is determined by the instrument used for such measurement. For example, in this case, we have the height of a small child being measured. We can use a simple ruler for this, and we see that a ruler has ten divisions for 1 cm. This means that the ruler cannot measure beyond the size of 0.1 cm or 1 mm. Hence, when we report the height of the small child, we report it to one significant digit after the decimal place. As an example, if we measure a child's height to be 90 full cm divisions and 8 smaller divisions, we report it as 90.8 cm but not 90.83 or 90.86 cm.
Answer:
Part a)

Part b)

Part c)

Part d)

Part e)

Explanation:
Part a)
Angular speed is given as



Part b)
Since turn table is accelerating uniformly
so we will have




Part c)
angular acceleration is given as



Part d)
When its angular speed changes to 120 rpm
then we will have


number of turns revolved is 15 times
so we have



Part e)
now for uniform acceleration we have



Answer:
A, B, and E
Explanation:
The springs are identical, and are compressed the same amount, so they have the same initial elastic potential energy. (E is true)
Energy is conserved, so the darts have the same amount of kinetic energy. (A is true, C is false)
The lighter dart has the same energy as the heavier dart. Since it has less mass, it must have a greater speed. (B is true, D is false)
Answer:
1.75 m/s
Explanation:
Momentum is conserved.
m₁ u₁ + m₂ u₂ = m₁ v₁ + m₂ v₂
(50 g) (15 m/s) + (600 g) (0 m/s) = (50 g) (-6 m/s) + (600 g) v
v = 1.75 m/s
Answer:
The Position of the object L = 0.172 m
Explanation:
The detailed explanation of the question is given in the attach document.