Question

1) The distance s moved by an object in time t may be given by the expression s=1/2at^2 where a is the acceleration of the object. State two conditions for this expression to apply to the motion of the object. 2) How does gravity affect the velocity of an object in free fall? 3) Falling object under free fall as shown in below figure. What is its velocity at that particular time? (Free fall acceleration, g = 9.81ms^-2) t = 0s;v = 0 ms -1 t = 1.00 s; v = -1 ms t = 3.00 s; v = ms-1 t = 4.00 s; v = ms-1 t = 5.00 s; v= ms?

Answer 1

A. The expression s=1/2at^2 applies to the motion of an object under two conditions: constant acceleration (a) and the absence of other external forces acting on the object.

B. The expression s=1/2at^2 is applicable when an object experiences constant acceleration (a) and is not subjected to any other external forces.

Step-by-step explanation:

The expression s=1/2at^2 is derived from the equations of motion under constant acceleration. For this expression to be accurate, the first condition is that the acceleration of the object (a) must remain constant during the time interval considered. This implies that no other forces, such as friction or air resistance, should significantly impact the object's motion.

The second condition is related to the absence of external forces. If there are additional forces acting on the object, the equation may not accurately describe its motion. The expression assumes that the only force influencing the object's motion is the constant acceleration represented by 'a.'

Gravity is one example of a force that can influence the motion of an object. In free fall, when an object is only under the influence of gravity, the expression s=1/2at^2 is applicable.

In summary, the expression s=1/2at^2 is valid when the object experiences constant acceleration (a) and is not subjected to other external forces beyond the specified conditions.