Question

<br />4. Complete the sentences and explain<br />them.<br />The minimum distance between<br />the start and finish points of the<br />motion of an object is called the<br />..... of the object.<br />b. Deceleration is -------- acceleration<br />When an object is in uniform<br />circular motion, its<br />changes at every point.<br />d. During collision .... remains<br />constant.<br />e. The working of a rocket depends<br />on Newton's ........ law of motion.<br />​.​

Answer 1

AnswEr :

a. The minimum distance between the start and finish points of the motion of an object is called the ..... of the object

• The minimum distance between the start and finish points of the motion of an object is called the Displacement of the object.

${\bold{\red{Explanation :}}}$Displacement is the shortest distance b/w initial and final position of an object.

b. Deceleration is -------- acceleration

• Deceleration is negative acceleration.

${\bold{\red{Explanation :}}}$Deceleration is the acceleration in the opposite direction to the direction of the velocity. [Negative ]

c. When an object is in uniform circular motion, its ..… changes at every point.

• When an object is in uniform circular motion, its direction changes at every point.

${\bold{\red{Explanation :}}}$It happens because the direction of a particle moving in a circle always changes at a constant rate.

d. During collision ....... remains constant.

• During collision momentum remains constant.

${\bold{\red{Explanation :}}}$According to the principle of conservation of momentum, system of particles does not experience any kind of external force, thus total momentum of the particles in the system remains constant.

e. The working of a rocket depends on Newton’s ….. law of motion.

• The working of a rocket depends on Newton’s third law of motion.

${\bold{\red{Explanation :}}}$As burning of fuel inside the rocket creates a forward push on the rocket. It creates an equal and opposite push on the exhaust gases. So, we can say that working of a rocket depends on Newton’s third law of motion.