An automobile traveling 95 overtakes a 1.10--long train traveling in the same direction on a track parallel to the road.
Q1: If the train's speed is 75 , how long does it take the car to pass it
Q2:How far will the car have traveled in this time?
Q3:What is the time if the car and train are traveling in opposite directions?
Q4:How far will the car have traveled if the car and train are traveling in opposite directions
relative speed:20mph distance 1.1
time=distance/speed=1.1/20 hrs
i got answers to some of the questions
Q1: 3.3 mins
Q2: ?km <- still need help with
Q3:23.3
Q4:?km still need help with
It is easier to solve this problem if we introduce the relative velocity of the car (relative to the train). The velocity of the car relative to the train is (95-75) km/h=20 km/h.
In the relative description the train is not moving and the car is moving with constant speed 20 km/h.
a. The time the car needs to pass the train is
t = length of the train/relative speed = 1.1 km/20 (km/h) = 0.055 h =198 s.
b. To find the actual traveled distance of the car we just need to multiply the traveled time (0.055 h) by the actual speed of the car:
L = 95•0.055 = 5.225 km
c. The relative speed is v1= 95+75 =170 km/h
The time the car needs to pass the train in this case is
t1= length of the train/relative speed v1= 1.1 km/170 (km/h)=
= 0.00647h =23.3 s.
d. To find the actual traveled distance of the car we just need to multiply the traveled time (0.00647 h) by the actual speed of the car:
L = 95•0.00647 = 0.615 km.
To answer these questions, we need to use the formula: speed = distance/time.
Q1: To find the time it takes for the car to pass the train, we can assume that when the car overtakes the train, they have both covered the same distance. Therefore, we can set up the equation:
95 = 75 * time (speed of the car = speed of the train = 75)
Solving for time, we divide both sides of the equation by 75:
time = 95/75
Therefore, it takes the car approximately 1.27 hours (or 1 hour and 27 minutes) to pass the train.
Q2: To find the distance the car traveled in this time, we multiply the speed of the car by the time:
distance = speed * time
distance = 95 * 1.27
Therefore, the car traveled approximately 120.65 miles.
Q3: If the car and train are traveling in opposite directions, their speeds are added to find the relative speed between them. In this case:
relative speed = speed of car + speed of train
relative speed = 95 + 75
Therefore, the relative speed is 170 mph.
To find the time when traveling in opposite directions, we can use the same formula:
time = distance/relative speed
Plugging in the length of the train (1.10 miles) divided by the relative speed (170 mph):
time = 1.10/170
Therefore, it takes the car approximately 0.0065 hours (or 0.39 minutes) to pass the train.
Q4: To find the distance the car traveled when traveling in opposite directions, we multiply the speed of the car and the time:
distance = speed * time
distance = 95 * 0.0065
Therefore, the car traveled approximately 0.6175 miles.