☰
✕

Laws of Motion
Question
Wired Faculty App

A rocket with a lift-off mass 20,000 kg is blasted upwards with an initial acceleration of 5.0 m s–2. Calculate the initial thrust (force) of the blast.
 

Answer

Mass of the rocket, m = 20,000 kg
Initial acceleration, a = 5 m/s2

Acceleration due to gravity, g = 10 m/s2

Using Newton’s second law of motion,
Net force (thrust) acting on the rocket is given by the relation, 
        F – mg = ma 

                 F = m (g + a)
                    = 20000 × (10 + 5)
                    = 20000 × 15
                    = 3 × 105 N

Sponsor Area

Some More Questions From Laws of Motion Chapter

Which law of motion is also called law of inertia?

What is measure of inertia of body?

Which law of motion defines the force?

What happens to a stone tied to the end of string and whirled in a circle if the string suddenly breaks?

Which law of motion gives the quantitative knowledge of force?

Which law of motion is the real law of motion?

Which law of motion gives the quantitative definition of force?

Why do we pull the rope in downward direction for climbing up?

What can set the body at rest into motion?

What do you mean by mechanically isolated system?