How Things Move? Learn The Science Behind Motion - Physics Quiz

Velocity is a vector quantity that represents the rate at which an object changes its position. It includes both magnitude (speed) and direction. Since velocity considers direction, it can be positive when an object is moving in one direction, negative when it is moving in the opposite direction, or zero when there is no motion. Therefore, the statement that velocity can be positive, negative, or zero is true.

The SI unit of velocity is meters per second (m/s). Velocity is a vector quantity that represents the rate at which an object changes its position with respect to time. The unit "m/s" indicates that the object is moving a certain distance (in meters) in a specific direction per unit of time (in seconds). This unit is widely used in scientific and everyday contexts to describe the speed and direction of objects in motion.

The SI unit of time is seconds. This is because seconds are a universally recognized and accepted unit for measuring time in the International System of Units (SI). It is a fundamental unit of time and is used in various scientific and everyday applications for precise and accurate measurements.

Yes, a body can have constant speed but variable velocity. Speed is a scalar quantity that only considers the magnitude of the motion, while velocity is a vector quantity that takes into account both the magnitude and direction of the motion. If the body is moving in a circular path at a constant speed, its velocity will be constantly changing because the direction of the motion is changing. Therefore, the body can have a constant speed but variable velocity.

Yes, an object moving in a certain direction can have acceleration in a perpendicular direction. This is because acceleration is a vector quantity that includes both magnitude and direction. Even though the object may be moving in one direction, it can still experience acceleration in a different direction due to external forces acting on it. This can cause the object to change its velocity or direction of motion, resulting in acceleration in a perpendicular direction.

If the speed-time graph is a straight line parallel to the time axis, it indicates that the object is in uniform motion. This means that the object is moving with a constant speed and there is no change in its velocity over time. In uniform motion, the object covers equal distances in equal intervals of time.

When the car is moving on a straight road, the distance moved and the magnitude of the displacement are equal. This is because in a straight line motion, the distance traveled is the actual path covered by the car, while the displacement is the shortest straight line distance between the initial and final positions. Since the car is moving in a straight line, the distance traveled and the displacement will be the same.

If the displacement of an object is proportional to the square of time, it means that the object is experiencing a constant acceleration. This is because the square of time represents a quadratic relationship, which is characteristic of uniform acceleration. In this case, the object's velocity is increasing at a constant rate over equal intervals of time. Therefore, the correct answer is uniform acceleration.

Yes, an object can have zero displacement even if it has moved through a distance. Displacement refers to the change in position of an object from its initial position to its final position, regardless of the path taken. If the object returns to its initial position after moving through a distance, its displacement will be zero. This can occur in situations where the object moves in a closed loop or completes a round trip.

The area occupied below the velocity/time graph represents the distance covered by the object. The graph shows the relationship between velocity and time, and the area under the graph represents the displacement or distance traveled by the object during that time interval. Therefore, the correct answer is distance covered by the object.

The SI unit of distance is meter (m). The meter is the fundamental unit of length in the International System of Units (SI) and is used to measure distances on a smaller scale. It is commonly used in scientific and everyday measurements, such as measuring the length of objects or distances between two points.

In a free fall, the velocity of a stone is increasing equally in equal intervals of time under the effect of gravitational force. This indicates that the stone is experiencing uniform acceleration. Uniform acceleration means that the stone's velocity is changing by the same amount in each interval of time, indicating a constant rate of change in velocity. Therefore, the correct answer is uniform acceleration.

The car is initially traveling at a speed of 90 km/h, which can be converted to 25 m/s. The brakes are applied to produce a uniform acceleration of -0.5 m/s^2. Using the equation of motion, v^2 = u^2 + 2as, where v is the final velocity, u is the initial velocity, a is the acceleration, and s is the distance, we can solve for s. Plugging in the values, we have 0 = (25)^2 + 2(-0.5)s. Simplifying, we get 0 = 625 - s. Rearranging the equation, we find s = 625 m. Therefore, the car will go 625 meters before it is brought to rest.

The acceleration can be calculated using the formula acceleration = change in velocity / time. In this case, the change in velocity is -2m/s and the time is 5s. Therefore, the acceleration is -2m/s divided by 5s, which simplifies to -0.4m/s^2.

The statement is false because when an object is in uniform motion, it means that the object is moving at a constant speed in a straight line, without any changes in its velocity. In uniform motion, the acceleration of the object is zero, as there is no change in velocity. Therefore, the acceleration of the object is not uniformly increasing.

The numerical ratio of displacement to distance for a moving object can be equal to 1 or less than 1. Displacement is a vector quantity that represents the change in position of an object in a specific direction. Distance, on the other hand, is a scalar quantity that represents the total path traveled by the object. In some cases, the displacement and distance may be equal, such as when the object moves in a straight line without changing direction. However, in most cases, the displacement will be less than the distance traveled, as the object may change direction or move back and forth.

Speed cannot be negative because it is a scalar quantity that only represents the magnitude of velocity. Velocity, on the other hand, is a vector quantity that includes both magnitude and direction. Therefore, speed can only be positive or zero, but not negative.

If the distance-time graph is a straight line parallel to the time axis, it indicates that the object is at rest. This means that the object is not moving and its position remains constant over time. In this case, there is no change in the distance traveled by the object, indicating that it is not in motion.

The speedometer of a car measures the instantaneous speed. Instantaneous speed refers to the speed of an object at a particular moment in time. In the context of a car, the speedometer provides the driver with real-time information about how fast the car is currently moving. It does not provide information about the average speed over a period of time or the velocity, which includes the direction of motion. Acceleration, on the other hand, is a measure of how quickly the speed of an object changes over time and is not directly measured by the speedometer.

The average velocity of a moving body can sometimes be zero if the body returns to its starting point after a certain period of time. This means that the displacement of the body is zero, indicating that it has not moved from its initial position. Therefore, option i is correct. The distance travelled by a moving body cannot be zero unless it remains stationary, so option ii is incorrect. The average speed of a moving body is the total distance travelled divided by the total time taken, so it cannot be zero unless the body does not move at all, making option iii incorrect. Displacement is the change in position of a body, so it can be zero if the body returns to its starting point, making option iv correct.

The correct answer is that velocity of a moving body is its speed in a given direction. Velocity is a vector quantity that includes both magnitude (speed) and direction. Speed, on the other hand, is a scalar quantity that only represents the magnitude of motion. Therefore, velocity takes into account the direction of motion while speed does not.

The motion of a body going round the sun with constant speed in a circular orbit is considered accelerated. This is because even though the speed remains constant, the direction of the body's velocity is constantly changing due to its circular path. Acceleration is defined as any change in velocity, which includes changes in direction. Therefore, the body is experiencing acceleration despite its constant speed.

Car B is the slowest because its distance-time graph has the least steep slope compared to the other cars. This indicates that Car B covers less distance in the same amount of time compared to the other cars, hence it is moving at a slower speed.

Based on the given speed-time graph, the area under the graph represents the distance covered by the car. By calculating the area under the graph, we find that the total distance covered by the car is 875 m.

An odometer is a device used to measure the distance traveled by a vehicle. It is typically found in the dashboard of a car and works by counting the number of rotations of the vehicle's wheels. The distance traveled is then displayed on the odometer's digital or analog screen. This device is commonly used by drivers to keep track of the distance they have traveled, which can be useful for various purposes such as calculating fuel efficiency or determining maintenance intervals.

The correct answer is "change in velocity/time" because acceleration is defined as the rate at which an object's velocity changes over time. It measures how quickly an object's velocity is changing, either by increasing or decreasing. Therefore, the change in velocity divided by the time taken gives us the acceleration of the object.

The motion of a racing car on a circular track is most likely not a case of uniform circular motion because the speed of the car is not constant throughout the track. In uniform circular motion, the object moves at a constant speed in a circular path, but in the case of a racing car, the speed can vary depending on the position of the car on the track and the actions of the driver.

If the velocity-time graph for the car is a horizontal line parallel to the time axis, it means that the velocity of the car remains constant over time. Therefore, the velocity of the car at the end of 25 s will still be 10 m/s, as it does not change.

False. An object can move with constant acceleration even when its velocity is zero. This can occur when the object is momentarily at rest or when it changes direction. For example, an object thrown upwards reaches its maximum height momentarily and its velocity becomes zero, but it still experiences a constant acceleration due to gravity. Similarly, an object moving in a circular path at a constant speed has a velocity of zero at the topmost point, but it still undergoes constant acceleration towards the center of the circle.

When a car is brought to rest by applying brakes, it experiences a negative acceleration or retardation. The formula to calculate retardation is given by the change in velocity divided by the time taken. In this case, the change in velocity is from 10 m/s to 0 m/s, which is a decrease of 10 m/s. The time taken is 20 seconds. Therefore, the retardation can be calculated as -10 m/s divided by 20 s, which equals -0.5 m/s^2. Since the question asks for the magnitude of the retardation, the answer is +0.5 m/s^2.

The average speed of an object is calculated by dividing the total distance traveled by the total time taken. In this case, the object travels 16 meters in 4 seconds and 16 meters in 2 seconds. Therefore, the total distance traveled is 16 + 16 = 32 meters, and the total time taken is 4 + 2 = 6 seconds. Dividing the total distance by the total time gives us an average speed of 32/6 = 6.

The displacement after half a circle would be 2r because the displacement is the shortest distance between the initial and final positions of the particle. In a circular path, the particle starts at one point and ends at the exact opposite point after completing half a circle. Since the diameter of a circle is twice the radius, the displacement after half a circle would be equal to twice the radius, which is 2r.

The given scenario states that the boy is enjoying a ride on a merry-go-round which is moving with a constant speed of 10 m/s. This implies that the boy is moving in a circular path, and since the direction of his motion is constantly changing, he is experiencing acceleration. Therefore, the correct answer is "in accelerated motion".

The acceleration of the bus can be calculated using the formula: acceleration = (final velocity - initial velocity) / time. In this case, the final velocity is 36 km/h, the initial velocity is 72 km/h, and the time is 5 seconds. Plugging in these values into the formula, we get: acceleration = (36 - 72) / 5 = -36 / 5 = -7.2. Therefore, the acceleration of the bus is 2.

When an object moves in a circle, the displacement refers to the change in position from the starting point to the ending point. If the displacement is 0, it means that the object has returned to its starting point after completing a full revolution. The distance traveled, on the other hand, refers to the total length of the path covered by the object. In this case, since the object has completed a full circle, the distance it has traveled will be equal to the circumference of the circle, which is given by the formula 2πr, where r is the radius of the circle. Therefore, the correct answer is 2πr.