Answer:
Definimos:
Rapidez media es igual al cociente entre la distancia recorrida y el tiempo que se tarda en recorrer esa distancia.
En este caso la distancia recorrida es 400m, y el tiempo que se tarda es 30s, entonces la rapidez media va a ser:
RM = 400m/30s = 13.33 m/s
La velocidad media por otro lado, es igual al cociente entre el desplazamiento y el tiempo necesario para desplazarse.
El desplazamiento es igual a la distancia entre la posición final y la posición inicial, que en este caso eso 40m, y el tiempo necesario sigue siendo 30s, entonces la velocidad media va a ser:
VM = 40m/30s = 1.33 m/s
The work done on the car is -20 J.
Work done on the car is negative, meaning that the car actually does work on the external system.
<h3>Energy and law of conservation of energy</h3>
- Energy is the ability to do work
- the law of conservation of energy states that the total energy in a system is conserved
From the law of conservation of energy, the initial energy of the car before it moves down the road remains constant or unchanged.
- Initial energy = 100 J
- Initial energy = Final energy - work done on car
- Final Energy = Work done on car + initial energy
80J = Work done on car + 100 J
Work done on car = 80 - 100J
Work done on car = -20 J
Hence, the work done on the car is -20 J
Work done on car is negative.
Since work done on the car is negative, it means that the car actually does work on the external system. Hence, the decrease in the energy of the car.
Learn more about energy and work at: brainly.com/question/13387946
B 20 m/s
It should go to 100 that fast nor 40
Answer;
-Economy
The condition of a country’s economy depends on its people’s ability to exchange money for goods and services.
Explanation;
Economy is the state of a country or region in terms of the production and consumption of goods and services and the supply of money.
An economy encompasses all activity related to production, consumption and trade of goods and services in an area. An economy applies to everyone from individuals to entities such as corporations and governments.
There are four different types of economies; traditional economy, market economy, command economy and mixed economy. Each type of economy has it’s own strengths and weaknesses.
Answer:
Explanation:
For simple pendulum the formula is

Where T is time period , l is length and g is acceleration due to gravity .

n is frequency
Putting the values


l = 1.584 m