1.
A person walks towards East for 10 meters and then towards North for 10 meters. The total displacement traveled is:
Correct Answer
B. 14.14 meters
Explanation
To find the total displacement, you can use the Pythagorean theorem because the person is moving both horizontally (East) and vertically (North).
The displacement is the hypotenuse of a right triangle where:
The horizontal displacement (East) is 10 meters.
The vertical displacement (North) is 10 meters.
Using the Pythagorean theorem:
Displacement = √(Horizontal^2 + Vertical^2) Displacement = √(10^2 + 10^2) Displacement = √(100 + 100) Displacement = √200 Displacement ≈ 14.14 meters
So, the total displacement traveled is approximately 14.14 meters, which is the closest to option 2: 14.14 meters.
2.
A person walks toward the west for 12 meters and then toward the north for 5 meters. The total displacement is:
Correct Answer
C. 13 meters
Explanation
To find the total displacement, you can use the Pythagorean theorem because the person is moving in two perpendicular directions (west and north). The Pythagorean theorem states that in a right-angled triangle, the square of the hypotenuse (the side opposite the right angle) is equal to the sum of the squares of the other two sides.
In this case:
- The displacement in the west direction is 12 meters.
- The displacement in the north direction is 5 meters.
So, the total displacement (d) is given by:
[ d = √(12^2 + 5^2)]
[ d = √(144 + 25)]
[ d = √{169}]
d = 13 meters
Therefore, the total displacement is 13 meters.
3.
Find the average speed of a car if it travels 30 meters in 10 seconds, then it travels another 50 meters in 30 seconds.
Correct Answer
B. 2 m/s
Explanation
The average speed of a car can be calculated by dividing the total distance traveled by the total time taken. In this case, the car travels a total distance of 30 meters + 50 meters = 80 meters in a total time of 10 seconds + 30 seconds = 40 seconds. Dividing 80 meters by 40 seconds gives us an average speed of 2 m/s.
4.
The velocity of a car traveling 40 meters in 5 seconds is
Correct Answer
C. 8 m/s
Explanation
The velocity of the car is 8 m/s because it traveled a distance of 40 meters in 5 seconds. The formula to calculate this is Velocity= Displacement/Time. Hence, 40/5= 8 m/s.
5.
The average velocity of a car that initially is traveling at 50 meters in 5 seconds and then 10 meters in 5 seconds is
Correct Answer
A. 6 m/s
Explanation
To calculate the velocity of a car, you can use the formula:
Velocity (v) = Distance (d) / Time (t)
First, calculate the velocity for the car's first movement:
Velocity for the first 50 meters = 50 meters / 5 seconds = 10 meters per second
Now, calculate the velocity for the car's second movement:
Velocity for the next 10 meters = 10 meters / 5 seconds = 2 meters per second
So, the velocity of the car when it traveled the first 50 meters was 10 meters per second, and the velocity when it traveled the next 10 meters was 2 meters per second.
The total change in position and time is 60m and 10 s. the average velocity is therefore 60/10 = 6 m/s
6.
The acceleration of a person going from 0 m/s to 25 m/s in 5 seconds is
Correct Answer
D. 5 m/s
Explanation
The acceleration of a person going from 0 m/s to 25 m/s in 5 seconds is 5 m/s. This can be calculated using the formula for acceleration, which is the change in velocity divided by the change in time. In this case, the change in velocity is 25 m/s - 0 m/s = 25 m/s, and the change in time is 5 seconds. Therefore, the acceleration is 25 m/s divided by 5 seconds, which equals 5 m/s.
7.
The acceleration of a person going from 50 m/s to 40 m/s in 10 seconds is
Correct Answer
A. -1 m/s2
Explanation
The acceleration of a person going from 50 m/s to 40 m/s in 10 seconds is -1 m/s2. This is because acceleration is calculated by dividing the change in velocity by the time taken. In this case, the change in velocity is -10 m/s (40 m/s - 50 m/s) and the time taken is 10 seconds. Therefore, the acceleration is -10 m/s divided by 10 seconds, which equals -1 m/s2.
8.
The average velocity for the first 10 seconds is
Correct Answer
D. 6 m/s
9.
The average velocity from 20 to 30 seconds is
Correct Answer
C. -4 m/s
Explanation
The average velocity from 20 to 30 seconds is -4 m/s. This means that over the time interval from 20 to 30 seconds, the object is moving at an average speed of 4 meters per second in the negative direction. The negative sign indicates that the object is moving in the opposite direction of the positive axis.
10.
The velocity equal to 0 m/s is
Correct Answer
B. 10-15s
Explanation
According to the graph, the velocity equal to 0 m/s occurs between the time of 10-15 seconds.