Answer: 
Explanation:
In the image attached with this answer are shown the given options from which only one is correct.
The correct expression is:

Because, if we derive velocity
with respect to time
we will have acceleration
, hence:

Where
is the mass with units of kilograms (
) and
with units of meter per square seconds
, having as a result 
The other expressions are incorrect, let’s prove it:
This result has units of
This result has units of
This result has units of
and
is a constant
This result has units of
This result has units of
This result has units of
and
is a constant
This result has units of
and
is a constant
because
is a constant in this derivation respect to
This result has units of
and
is a constant
Answer: 
Explanation:
The confidence interval for population mean is given by :-

Given : Sample size : 
Sample mean : 
Standard deviation : 
Significance level : 
Critical value : 
Now, the 95% confidence interval estimate of the (true, unknown) mean sound intensity of all food processors of this type :-

Explanation:
Given that,
Mass of the block, m = 12.2 kg
Initial velocity of the block, u = 6.65 m/s
The coefficient of kinetic friction, 
(a)The force of kinetic friction is given by :

mg is the normal force
So,

(b) Net force acting on the block in the horizontal direction,
f = ma
a is the acceleration of the block

(c) Let d is the distance covered by the block before coming to the rest. Using third equation of motion as follows :

Hence, this is the required solution.
Power is energy per unit time. Therefore, D is the correct one