According to thermodynamics, if a system exchanges matter and energy with its environment it is an open system. For example, human beings and animals can be considered as open systems, since we take chemical energy in the form of food and perform work on our surrounding environment when moving and doing activities.

7 0

3 years ago

The most likely region of the radio spectrum for communication with other civilizations is in the "water hole."

Salsk061 [2.6K]

Answer:

Radio emissions of hydrogen and OH molecules

Explanation:

Water hole is a quiet region of the electromagnetic spectrum

8 0

3 years ago

In an arcade game a 0.135 kg disk is shot across a frictionless horizontal surface by compressing it against a spring and releas

ioda

Answer:

v=2.42m/s

Explanation:

We use the energy conservation theorem in order to solve the problem. The energy when the spring is compressed is equal at the energy when the disk leaves the spring:

$E_{initial}=E{final}\\E_{k-initial}+E_{p-initial}=E_{k-final}+E_{p-final}\\0+\frac{1}{2}kx^2=\frac{1}{2}mv^2+0$

At the beginning the initial energy is totally potential, energy linked to the compressed spring. At the end the energy is totally kinetics

We solve the equation in order to find the speed.

k=162 N/m

x=7 cm=0.07m

m=0.135 kg

$v=x*\sqrt{k/m}=0.07*\sqrt{162/0.135}=2.42m/s$

6 0

3 years ago