Answer:
the acceleration of the race car is 2 m/s²
Explanation:
Given;
initial velocity of the race car, u = 44 m/s
final velocity of the race car, v = 66 m/s
time of motion of the race car, t = 11 s
The acceleration of the race car is calculated as;

Therefore, the acceleration of the race car is 2 m/s²
Answer:
162.78 m/s is the most probable speed of a helium atom.
Explanation:
The most probable speed:

= Boltzmann’s constant =
T = temperature of the gas
m = mass of the gas particle.
Given, m = 
T = 6.4 K
Substituting all the given values :


162.78 m/s is the most probable speed of a helium atom.
Drift velocity is equal to displacement of the moving object per unit time. The SI unit for displacement is meters while that of time is second. Hence the derived SI unit of velocity is meter per second. This also applies to electron mobility which relates to the displacement per unit time of a moving electron