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The equation for the kinetic energy of a falling object is kinetic energy=1/2 an object's mass multiplied by it's speed squared. From this, we can work out the speed. First you need to know its weight and its kinetic energy. The kinetic energy is obtained by working out it's potential energy before it fell (Potential energy= mass multiplied by gravitational pull multiplied by height. Then, at whatever point during the fall, the decrease in potential energy marks the increase in kinetic energy. From then we work out the speed.
Example; An object that weighs 8.1 kilograms is 10 metres above the ground. It's potential energy is therefore 8.1x10(gravitational pull on earth is always 10)x10. So it has a potential energy of 810 joules. it falls 5 metres, so it's potential energy is 8.1x10x5 (405 joules). The total energy, we know, is 810J, so 810-a05=405, giving it kinetic energy of 405J. The kinetic energy formula is then rearranged as speed squared=kinetic energy/ 0.5m.
Our equation is therefore speed squared= 405/4.05, so speed squared=100. The square root of 100 is 10 so the speed is 10 metres per second (36 kilometres per hour).
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How does the displacement of a falling object change with time?
for a freely falling object displacement(s)=(1/2)gt^2. (g=acceleation due to gravity) if an object is given initial velocity(u) then displacement equation is s=ut+(1/2)gt^2.
How do you find the total time that on object is in the air with an initial velocity?
You can use the equation v = u + at from kinematics v = final velocity, which in this case is 0 because the object eventually hits the floor. u = initial velocity which is given to you a = acceleration which is always 9.8m/s^2 when dealing with falling objects t = time. manouver the equation and solve for time. Keep in mind that I havn't taken into account movement in the x-y direction and assumed that it is just a falling object falling in the -y direction. CG
What is the surface area of a falling object?
It depends on the object!
Is (7 -1) a solution to the equation y -7x?
[object Object]
Is it true that the thing that affects how fast it falls is the objects surface area?
Surface area is ONE thing that can affect how fast an object falls. Two forces determine how fast an object falls - the force of gravity and the opposing drag on the object from the medium it is falling through. In the case of an object falling in a vacuum, there is no drag so the object falls strictly according to the law of gravity. If an object is dropped through a fluid such as air or water, it can reach a terminal velocity where the force of gravity is exactly counterbalanced by the opposing drag on the object. In this case acceleration ceases - although motion does not. In other words, the object continues to fall, but it doesn't speed up. Drag force is a function of object velocity, viscosity of the fluid it is falling through, the surface area of the falling object, the surface roughness of the falling object, and the geometry of the falling object (spheres usually have less drag than cubes for example).
