Question

З пункту А виїхав мотоцикліст, а через 1,5 год услід за ним - автомобіль.Швидкість автомобіля дорівнює 80км/год, а швидкість мотоцикліста - 40 км/год.Через який час після свого виїзду автомобіль наздожене мотоцикліста?

Answer 1

Т.е. мотоциклист проехал 40*1.5=60км.

Тогда автомобиль едет быстрее на 80-40=40км/ч

И он сократит растояние в 60км, за 60/40=1.5часа.

Ответ: догонит через 1.5часа.

Answer 2

Problem Analysis

We are given that a motorcyclist starts from point A and after 1.5 hours, a car starts following the motorcyclist. The car's speed is 80 km/h, and the motorcyclist's speed is 40 km/h. We need to determine how long it will take for the car to catch up to the motorcyclist.

Solution

To solve this problem, we can use the concept of relative speed. The relative speed is the difference between the speeds of two objects moving in the same direction. In this case, the car is moving faster than the motorcyclist, so the relative speed will be the difference between their speeds.

The relative speed of the car with respect to the motorcyclist is 80 km/h - 40 km/h = 40 km/h.

To find the time it takes for the car to catch up to the motorcyclist, we can use the formula:

Time = Distance / Speed

Since the car is catching up to the motorcyclist, the distance between them will be decreasing. Therefore, we need to find the time it takes for the distance between them to become zero.

Let's assume that the time it takes for the car to catch up to the motorcyclist is t hours. During this time, the motorcyclist will have traveled a distance of 40 km/h * t, and the car will have traveled a distance of 80 km/h * t.

Setting these distances equal to each other, we can solve for t:

40 km/h * t = 80 km/h * t

Simplifying the equation:

40 km/h * t - 80 km/h * t = 0

-40 km/h * t = 0

Dividing both sides by -40 km/h:

t = 0

The equation t = 0 means that the car catches up to the motorcyclist at the same time it starts following the motorcyclist. This is because the car is moving faster than the motorcyclist, so it will catch up to the motorcyclist as soon as it starts moving.

Therefore, the car will catch up to the motorcyclist immediately after it starts following the motorcyclist.

Answer

The car will catch up to the motorcyclist immediately after it starts following the motorcyclist.