Question

Изменение скорости тела массой 2кг джижущегося по оси x описывается формулой vx= vox+axt где vox=8м/с ax =-2м/с в квадрате t время в секундах кинетическая энергия тела через 3 с после начала движения равна

Answer 1

V=8-2*3=2 м/с
E=m*V^2/2=2*4/2=4 Дж

Answer 2

Calculation of Kinetic Energy

To calculate the kinetic energy of an object, we need to know its mass and velocity. In this case, the mass of the object is given as 2 kg, and the velocity is described by the formula `vx = vox + axt`, where `vox = 8 m/s` and `ax = -2 m/s^2`. We need to find the kinetic energy of the object after 3 seconds of motion.

The formula for kinetic energy is `KE = (1/2) * m * v^2`, where `m` is the mass of the object and `v` is its velocity.

To find the velocity `v` after 3 seconds, we can substitute the given values into the formula `vx = vox + axt`:

`vx = vox + ax * t` `vx = 8 m/s + (-2 m/s^2) * 3 s` `vx = 8 m/s - 6 m/s` `vx = 2 m/s`

Now that we have the velocity `v`, we can calculate the kinetic energy `KE`:

`KE = (1/2) * m * v^2` `KE = (1/2) * 2 kg * (2 m/s)^2` `KE = (1/2) * 2 kg * 4 m^2/s^2` `KE = 4 kg * m^2/s^2` `KE = 4 J`

Therefore, the kinetic energy of the object after 3 seconds of motion is 4 Joules.