Question

Se lanza hacia abajo un cuerpo de masa 2 kg con una velocidad de 1 m/s

Answer 1

Given that,

Mass = 2 kg

Height = 10 m

Speed = 1 m/s

We need to calculate the initial energy

Using formula of potential energy

$P.E=mgh$

$P.E=2\times9.8\times10$

$P.E=196\ J$

We need to calculate the final energy

Using formula of kinetic energy

$K.E=\dfrac{1}{2}mv^2$

Put the value into the formula

$K.E=\dfrac{1}{2}\times2\times1^2$

$K.E=1\ J$

We need to calculate the velocity when it is traveling 3 meters

Using conservation of energy

$E_{i}=E_{f}$

$mgh=\dfrac{1}{2}mv^2$

$v^2=2\times g\times h$

Put the value into the formula

$v^2=2\times9.8\times3$

$v=\sqrt{2\times9.8\times3}$

$v=7.66\ m/s$

Hence, The initial and final energy are 196 J and 1 J.

The speed of the particle is 7.76 m/s.