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Select the correct equation(s) that relate(s) the final and initial velocity of a freely falling object with respect to time. (A) s=ut+2at2 (B) v=u+21тАЛat (C) (vтИТu)=at
Only (A)
and (B)
and (C)
Only (C)
Only (C)
The relationship between velocity, acceleration, and time for an object under uniform acceleration is defined by the first equation of motion, v=u+at. Rearranging this equation to isolate the change in velocity gives (vтИТu)=at.
The relationship between velocity, acceleration, and time for an object under uniform acceleration is defined by the first equation of motion, v=u+at. Rearranging this equation to isolate the change in velocity gives (vтИТu)=at.
If you are driving a car and increase your speed from 20 km/h to 60 km/h over 10 seconds, the 'gain' in your velocity is directly proportional to how hard you press the accelerator (acceleration) and for how long you press it (time).
v=u+at тАФ First equation of motion
(vтИТu)=at тАФ The equation relating the change in velocity to acceleration and time
According to Newton's law of motion, acceleration is the rate of change of velocity: a=tvтИТuтАЛ. By multiplying both sides by time t, we obtain the expression (vтИТu)=at, where v is final velocity, u is initial velocity, a is acceleration, and t is time.
Acceleration is defined as the change in velocity per unit time.
For a freely falling object, the acceleration a is equal to the acceleration due to gravity g (approx 9.8m/s2).
The equation (vтИТu)=at is a direct derivation of the basic kinematic definition of acceleration.
Allows for simple calculation of final velocity when initial velocity, acceleration, and time are known.
Only applicable under conditions of uniform acceleration.
Calculating impact speed of falling objects
Analyzing motion in free-fall experiments
Option (A) is incorrect because the standard kinematic equation is s=ut+21тАЛat2.
Option (B) is incorrect because the factor 21тАЛ belongs to the displacement equation, not the velocity-time relationship.
D is correct тАФ The equation (vтИТu)=at correctly represents the change in velocity resulting from constant acceleration over a period of time.
Always verify units when working with kinematic equations; ensure time is in seconds and acceleration is in m/s2 to get velocity in m/s.