Question

На сколько уменьшится за 2с потенциальная энергия тела массой 1,5 кг при его свободном падении с некоторой высоты? Начальная скорость тела равна нулю.

Answer 1

Дано
t=2c
m=1,5кг
Найти ΔЕп
ΔЕп=mgh, где g - ускорение свободного падения, g =10м/с². h- высота, на которую опуститится тело за 2 секунды свободного падения.
h=gt²/2
ΔЕп=mg*gt²/2=m(gt)²/2=1,5кг*(10м/с²*2с)²/2=1,5кг*(20м/с)²/2=1,5кг*400м²/с²/2= 1,5*200Дж=300Дж

Answer 2

Calculation of Potential Energy

To calculate the change in potential energy of an object during free fall, we can use the formula:

ΔPE = mgh

Where: - ΔPE is the change in potential energy - m is the mass of the object - g is the acceleration due to gravity (approximately 9.8 m/s^2 on Earth) - h is the height from which the object falls

In this case, the mass of the object is 1.5 kg, and the initial velocity is zero. We need to find the change in potential energy after 2 seconds of free fall.

Using the formula, we can calculate the change in potential energy as follows:

ΔPE = mgh = (1.5 kg) * (9.8 m/s^2) * h

To find the value of h, we can use the equation of motion for free fall:

h = (1/2) * g * t^2

Where: - t is the time of free fall (2 seconds in this case)

Substituting the value of t into the equation, we get:

h = (1/2) * (9.8 m/s^2) * (2 s)^2 = 19.6 m

Now we can substitute the value of h into the formula for potential energy:

ΔPE = (1.5 kg) * (9.8 m/s^2) * (19.6 m) = 284.04 J

Therefore, the change in potential energy of the object with a mass of 1.5 kg after 2 seconds of free fall from a certain height is approximately 284.04 Joules.