26. D. crushing the sugar cube and dissolving it in water.
27. A. atom
28. B. molecule
29. B. plum pudding model of Joseph John Thomson
30. B. He used cathode ray tubes which showed that all atoms contain tiny negatively charged subatomic particles or electrons.
31. D. protons and neutrons are relatively heavier than electrons.
Answer:
the acceleration 
Explanation:
Given that:
the initial speed v₁ = 0 m/s i.e starting from rest ; since the car accelerates at a distance Δx = 6 miles in order to teach that final speed v₂ of 63.15 km/h.
So; the acceleration for the first 6 miles can be calculated by using the formula:
v₂² = v₁² + 2a (Δx)
Making acceleration a the subject of the formula in the above expression ; we have:
v₂² - v₁² = 2a (Δx)




Thus;
Assume the car moves in the +x direction;
the acceleration 
Answer:
Part a)


Part b)

Explanation:
Part a)
Constant speed by which the student will run is given as

now after some time if student is going to overtake the position of bus
so here the final positions will be same
so we have




so it is

So student will run the total distance



Part b)
Speed of bus when student reach the bus is given as



Answer:
i = 0.477 10⁴ B
the current flows in the counterclockwise
Explanation:
For this exercise let's use the Ampere law
∫ B . ds = μ₀ I
Where the path is closed
Let's start by locating the current vines that are parallel to the z-axis, so it must be exterminated along the x-axis and as the specific direction is not indicated, suppose it extends along the y-axis.
From BiotSavart's law, the field must be perpendicular to the direction of the current, so the magnetic field must go in the x direction.
We apply the law of Ampere the segment parallel to the x-axis is the one that contributes to the integral, since the other two have an angle of 90º with the magnetic field
Segment on the y axis
L₀ = (y2-y1)
L₀ = 3-0 = 3 cm
Segment on the point x = 2 cm
L₁ = 3-0
L₁ = 3cm
B L = μ₀ I
B 2L = μ₀ I
i = 2 L B /μ₀
i= 2 0.03 / 4π 10⁻⁷ B
i = 4.77 10⁴ B
The current is perpendicular to the magnetic field whereby the current flows in the counterclockwise
Since momentum is a vector quantity, take any direction as positive and other as negative. Answer won't change.