Question

The unit of the ratio between thrust and impulse is same as that of
1. frequency
2. speed
3. wavelength
4. acceleration

Answer 1

Correct Answer - Option 1 : frequency

CONCEPT:

• Thrust: The force acting perpendicular to the surface of the object is called thrust.
  • When any object is put into the water then the object will replace the water the same as it’s volume and the cause of which there is a force acting upwards, to balance this weight is called the thrust force.
  • Thrust is a kind of pull force, which is applied by the medium on the object.
  • It is a type of force so the SI unit of thrust is Newton (N).
  • The dimensional formula of Thrust is [ MLT^-2]
  • The effect of thrust is more on the smaller surface area than the thrust acting on a larger surface area. 

Thrust Force (FT) = Pressure (P) × Area (A)

• Impulse:
  • When a large force acts for a very small time, it causes a change in momentum. This is called Impulse.
  • Impulse(J) = Force x time duration = Change in momentum. 
  • Dimension = MLT-1.
• The dimension of Impulse is the same as momentum.

EXPLANATION:

• The dimensional formula of Thrust is [ MLT-2] and the Dimension of Impulse is MLT^-1.
• The unit of the ratio between thrust and impulse is 

\(\Rightarrow \frac{Thrust}{Impulse} = \frac{MLT^{-2}}{MLT^{-1}}= T^{-1}\)

• T^-1 is the unit of frequency. Therefore option 1 is correct.