Answer:
Statements 4, 6 & 7 are incorrect.
Explanation:
In any elastic collision, the overall momentum vector sum of the system remains zero.
In this scenario, an elastic collision occurs between the ball and a stationary wall. The ball's velocity will consistently revert after the impact, leading to a change in direction of momentum.
The initial momentum of the ball is represented as:

where:
m = mass of the ball
v = initial velocity of the body
post-collision for the elastic interaction:

- Here, the momentum changes solely in direction, thus contradicting statement 7.
- During the impact, both the ball and the wall exert forces on each other that are equal and opposite. The wall remains motionless, while the ball is influenced by the wall's reaction force, performing work on it, which contradicts statement 4.
- Given that this collision is elastic, the ball's form and dimensions do not alter.
- The previous points clearly indicate that not all provided statements hold true, thus violating statement 6.
Response:
0.9 cm
Clarification:
The following illustrates the calculation of the combined rod's length increase:
As established
Length increase = expansion of aluminum rod + expansion of steel rod

= 0.9 cm
We simply summed the expansions of both the aluminum and steel rods to determine the overall increase in the joined rod's length, which must be factored in
Answer:
The potential energy tied to the charge diminishes.
The electric field performs negative work on the charge.
Explanation:
Answer:
The answer to the specified question will be "
".
Explanation:
Referring to the question,
⇒ 
⇒
...(equation 1)

⇒ 
⇒
...(equation 2)
Now,
From equation 1 and equation 2, we conclude
⇒ 
By substituting the value of
, we derive
⇒ 
⇒ 