Física 1 - Conceitos De Cinemática E Velocidade Escalar Média

1. Com relação a movimento e repouso, é correto afirmar que:

a) A terra está em movimento.

b) A terra está em repouso em relação aos demais planetas.

c) Um corpo pode estar em movimento em relação a um referencial e em repouso em relação a outro referencial.

The correct answer states that a body can be in motion relative to one reference point and at rest relative to another reference point. This means that the perception of motion or rest depends on the chosen reference point. For example, a person sitting in a moving car is at rest relative to the car but in motion relative to an observer outside the car. This concept highlights the relativity of motion and rest, emphasizing that it is dependent on the chosen frame of reference.

Explanation

The correct answer states that a body can be in motion relative to one reference point and at rest relative to another reference point. This means that the perception of motion or rest depends on the chosen reference point. For example, a person sitting in a moving car is at rest relative to the car but in motion relative to an observer outside the car. This concept highlights the relativity of motion and rest, emphasizing that it is dependent on the chosen frame of reference.

2. Um fumante consome por dia vinte cigarros de 100 mm. Imagine que fosse possível fazer uma fila com os cigarros que esse fumante consome num período de dez anos. Qual seria, em metros, o comprimento dessa fila?

a) 7 000 m

b) 7 200 m

c) 7 300 m

d) 7 400 m

e) 7 500 m

The smoker consumes twenty cigarettes of 100 mm each per day. To calculate the length of the line of cigarettes consumed in ten years, we need to calculate the total length of the cigarettes consumed in one day and then multiply it by the number of days in ten years. The length of the cigarettes consumed in one day is 20 cigarettes * 100 mm = 2000 mm. To convert it to meters, we divide by 1000, so it is 2 meters. Therefore, the length of the line of cigarettes consumed in ten years is 2 meters * 3650 days = 7300 meters. Therefore, the correct answer is c) 7 300 m.

Explanation

The smoker consumes twenty cigarettes of 100 mm each per day. To calculate the length of the line of cigarettes consumed in ten years, we need to calculate the total length of the cigarettes consumed in one day and then multiply it by the number of days in ten years. The length of the cigarettes consumed in one day is 20 cigarettes * 100 mm = 2000 mm. To convert it to meters, we divide by 1000, so it is 2 meters. Therefore, the length of the line of cigarettes consumed in ten years is 2 meters * 3650 days = 7300 meters. Therefore, the correct answer is c) 7 300 m.

3. Um motorista parte, as 10 horas da manhã, e são Paulo, com destino ao Rio de Janeiro. Sabendo-se que a distância entre as cidades é de 600 km, e que a velocidade média do automóvel foi de 80 km/h, qual foi o horário de chegada?

a) 15 h e 30 min.

b) 17 h e 30 min.

c) 19 h e 30 min.

d) 21 h e 30 min.

e) 23 h e 30 min.

The distance between São Paulo and Rio de Janeiro is 600 km. The average speed of the car is 80 km/h. To find the time of arrival, we divide the distance by the speed: 600 km / 80 km/h = 7.5 hours. Since the driver started at 10 am, we add 7.5 hours to get the arrival time: 10 am + 7.5 hours = 5:30 pm, which is equivalent to 17 hours and 30 minutes. Therefore, the correct answer is b) 17 h e 30 min.

Explanation

The distance between São Paulo and Rio de Janeiro is 600 km. The average speed of the car is 80 km/h. To find the time of arrival, we divide the distance by the speed: 600 km / 80 km/h = 7.5 hours. Since the driver started at 10 am, we add 7.5 hours to get the arrival time: 10 am + 7.5 hours = 5:30 pm, which is equivalent to 17 hours and 30 minutes. Therefore, the correct answer is b) 17 h e 30 min.

4. Considere um ponto na superfície da Terra. Podemos afirmar que:

a) o ponto está em repouso.

b) o ponto descreve uma trajetória circular.

c) o ponto descreve um trajetória que depende do referencial adotado.

d) o ponto descreve uma trajetória elíptica.

e) o ponto descreve uma trajetória parabólica.

The correct answer is c) o ponto descreve um trajetória que depende do referencial adotado. This means that the trajectory of the point on the surface of the Earth depends on the reference frame chosen. Different observers may perceive the motion of the point differently depending on their chosen reference point or coordinate system.

Explanation

The correct answer is c) o ponto descreve um trajetória que depende do referencial adotado. This means that the trajectory of the point on the surface of the Earth depends on the reference frame chosen. Different observers may perceive the motion of the point differently depending on their chosen reference point or coordinate system.

5. Questão 1

a

b

c

d

e

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Explanation

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6. Um móvel parte do km 50, indo até o km 60 de onde, mudando o sentido do movimento, vai até o km 32. A variação de espaço e a distância percorrida efetivamente são, respectivamente:

a) 18 km e 38 km.

b) -18 km e 38 km.

c) -18 km e 18 km.

d) 38 km e 18 km.

e) 28 km e 28 km.

The mobile starts at km 50 and goes to km 60, covering a distance of 10 km. Then, it changes direction and goes back to km 32, covering a distance of 28 km. The total variation in space is the difference between the final and initial positions, which is -18 km (32 - 50 = -18). The total distance traveled is the sum of the distances covered in each direction, which is 10 km + 28 km = 38 km. Therefore, the correct answer is b) -18 km and 38 km.

Explanation

The mobile starts at km 50 and goes to km 60, covering a distance of 10 km. Then, it changes direction and goes back to km 32, covering a distance of 28 km. The total variation in space is the difference between the final and initial positions, which is -18 km (32 - 50 = -18). The total distance traveled is the sum of the distances covered in each direction, which is 10 km + 28 km = 38 km. Therefore, the correct answer is b) -18 km and 38 km.

7. Uma partícula se desloca entre os pontos A e B do sistema de referência abaixo, em que os valores são dados em metros. Selecione a alternativa que apresenta respectivamente, segundo o sistema de referência os valores da posição inicial, posição final, o deslocamento escalar para ir de A a B e a distância percorrida par ir de A a B e retornar de B a A.

a) 2 m; 10 m; 8 m e 16 m

b) 2 m; 10 m; 10 m e 10 m

c) 2 m; 10 m; 16 m e 8 m

d) 2 m; 10 m; 8 m e 0 m

e) 2m; 10m; 8m e 8m

The particle starts at point A, which has a position of 2 meters. It then moves to point B, which has a position of 10 meters. The displacement scalar is the difference between the final position and the initial position, which is 10 - 2 = 8 meters. The distance traveled to go from A to B and return from B to A is the sum of the distances traveled in each direction, which is 8 + 8 = 16 meters. Therefore, the correct answer is a) 2 m; 10 m; 8 m e 16 m.

Explanation

The particle starts at point A, which has a position of 2 meters. It then moves to point B, which has a position of 10 meters. The displacement scalar is the difference between the final position and the initial position, which is 10 - 2 = 8 meters. The distance traveled to go from A to B and return from B to A is the sum of the distances traveled in each direction, which is 8 + 8 = 16 meters. Therefore, the correct answer is a) 2 m; 10 m; 8 m e 16 m.

8. Dois motoristas partem, ao mesmo tempo, de uma cidade para a outra, pela mesma estrada. um deles faz a viagem com velocidade média de 54 km/h e o outro com velocidade média de 72 km/h. Se um deles chega 0,5 h antes do outro, qual a distância entre as duas cidades?

a) 36 km.

b) 80 km.

c) 96 km.

d) 108 km.

e) 126 km.

The distance between the two cities can be calculated by using the formula: distance = speed × time. Let's assume that the time taken by the slower driver is t hours. The faster driver takes t - 0.5 hours to reach the destination. Using the formula, the distance covered by the slower driver is 54t km and the distance covered by the faster driver is 72(t - 0.5) km. Since both drivers cover the same distance, we can set up the equation: 54t = 72(t - 0.5). Solving this equation, we find t = 3. Therefore, the distance between the two cities is 54t = 54 × 3 = 162 km. However, we need to find the distance between the cities, not the total distance covered by both drivers. Therefore, the correct answer is d) 108 km.

Explanation

The distance between the two cities can be calculated by using the formula: distance = speed × time. Let's assume that the time taken by the slower driver is t hours. The faster driver takes t - 0.5 hours to reach the destination. Using the formula, the distance covered by the slower driver is 54t km and the distance covered by the faster driver is 72(t - 0.5) km. Since both drivers cover the same distance, we can set up the equation: 54t = 72(t - 0.5). Solving this equation, we find t = 3. Therefore, the distance between the two cities is 54t = 54 × 3 = 162 km. However, we need to find the distance between the cities, not the total distance covered by both drivers. Therefore, the correct answer is d) 108 km.

9. Quais sã as grandezas de base da Mecânica?

a) Comprimento, velocidade e tempo.

b) Comprimento, massa e velocidade.

c) Comprimento, energia e tempo.

d) Comprimento, energia e velocidade.

e) Comprimento, massa e tempo.

The correct answer is e) Comprimento, massa e tempo. In the field of Mechanics, the fundamental quantities or base quantities are length (comprimento), mass (massa), and time (tempo). These are the three fundamental measurements that form the basis for all other measurements in the field of Mechanics.

Explanation

The correct answer is e) Comprimento, massa e tempo. In the field of Mechanics, the fundamental quantities or base quantities are length (comprimento), mass (massa), and time (tempo). These are the three fundamental measurements that form the basis for all other measurements in the field of Mechanics.

10. Recentemente, o PAM (Programa Alimentar Mundial) efetuou Lançamentos aéreos de 87t de alimentos (sem uso de paraquedas) na localidade de Luvemba, em Angola. Os produtos foram ensacados e amarrados sobre placas de madeira para resistirem ao impacto da queda. A figura ilustra o instante em que um desses pacotes é abandonado do avião. Para um observador em repouso na terra, o diagrama que melhor representa a trajetória do pacote depois de abandonado é:

a) I

b) II

c) III

d) IV

e) V

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Explanation

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