Question

1. An automobile is moving at 80km/h and a truck is moving at 60km/h approaching an automobile, what is the relative velocity of an automobile with respect to truck when the observer on the automobile measures it? Answer:-. Explanation:-​

Answer 1

The relative velocity of the automobile with respect to the truck, when measured by an observer in the automobile, is 140 km/h.

Step-by-step explanation:

To calculate the relative velocity of an automobile with respect to a truck, you have to take the velocity of one object and subtract the velocity of the other, assuming they are in a straight line and in opposite directions. Since the automobile is moving at 80 km/h and the truck is moving towards the automobile at 60 km/h, the relative velocity as measured by an observer in the automobile is the speed of the automobile (80 km/h) minus the speed of the truck (-60 km/h). Here, the negative sign indicates that the truck is moving in the opposite direction to the motion of the automobile.

Using the velocity addition rule, VAT = VA - VT, where VAT is the velocity of the automobile relative to the truck, VA is the velocity of the automobile, and VT is the velocity of the truck. In this case, VAT = 80 km/h - (-60 km/h) = 140 km/h.

Therefore, the relative velocity of the automobile with respect to the truck is 140 km/h.

Answer 2

The relative velocity of the automobile with respect to the truck, as measured by an observer in the automobile, is 140km/h towards the automobile's direction, by adding the speeds since they are moving directly towards each other.

Step-by-step explanation:

When an observer on the automobile measures the relative velocity of the automobile with respect to the truck, the motion of both vehicles should be taken into account. Since they are approaching each other, their velocities will be summed if one is moving in the opposite direction relative to the other in a straight line.

If the automobile is moving at 80km/h, and the truck is moving at 60km/h, then the relative velocity measured by an observer in the automobile towards the truck is 80km/h + 60km/h, which equals 140km/h.

To find the relative velocity, we use the formula: Vrelative = Vautomobile + Vtruck, where Vtruck is taken as a positive value because it is approaching the automobile.

Therefore, the relative velocity of the automobile with respect to the truck is 140 km/h towards the automobile's direction of motion.