MCQ: Equations of Motion - Class 9 MCQ

Topic in NCERT: Graphical Representation of Motion

Line in NCERT: error Occcured while getting response from embedding

Velocity acquired by the two bodies falling from rest through a distance his given as v = 

Given that :

Initial velocity, u = 0.2 m/s. 

Final velocity, v = 0 

Acceleration, a = 0.02 m/s^2.

v = u + at 

0 = 0.2 - 0.02 x t

0.02 x t = 0.2 

t = 0.2 / 0.02 = 10 sec.

Thus, the body will take 10 seconds to stop.

Topic in NCERT: Uniform Circular Motion

Line in NCERT: "If you carefully note, on being released the stone moves along a straight line tangential to the circular path."

Yes this is because we need to observe the motion of object or rest of object from any point called reference point.

Topic in NCERT: Describing Motion

Line in NCERT: "We describe the location of an object by specifying a reference point."

Consider a velocity - time graph for a uniformly accelerated body starting from rest is represented as follows.

u = velocity at time t1 
v =  velocity at time t2 
If acceleration is represented as a, then, acceleration is defined as the rate of change in velocity. 
⇒  a = v-u / t2 - t1 
⇒ a = v-u /t 
Or,v-u = at 
⇒ v= u + at 

Topic in NCERT: VELOCITY-TIME GRAPHS

Line in NCERT: "The area under the velocity-time graph gives the distance (magnitude of displacement) moved by the car in a given interval of time."

This is because in circular motion body is continuously changing its speed and acceleration is the change of velocity.

Topic in NCERT: UNIFORM CIRCULAR MOTION

Line in NCERT: "When an object moves in a circular path with uniform speed, its motion is called uniform circular motion."