Two cars start at the same time from the same location and go in the same direction. The speed of the first car is 50 km/h and the speed of the second car is 60 km/h. The number of hours it takes for the distance between the two cars to be 20 km is ___________.
Car Speed Distance Time Calculation
Determine the time required for the distance between two cars traveling in the same direction to become 20 km.
Relative Speed Calculation
The speeds of the two cars are $v_1 = 50$ km/h and $v_2 = 60$ km/h. Since they move in the same direction, the relative speed ($v_{rel}$) at which the distance between them increases is:
$ v_{rel} = v_2 - v_1 $
$ v_{rel} = 60 \text{ km/h} - 50 \text{ km/h} = 10 \text{ km/h} $
Time Calculation
The target distance ($D$) is 20 km. The time ($t$) needed to cover this distance at the relative speed is found using the formula $D = v_{rel} \times t$.
$ t = \frac{D}{v_{rel}} $
Substituting the values:
$ t = \frac{20 \text{ km}}{10 \text{ km/h}} $
$ t = 2 \text{ hours} $
Therefore, it takes 2 hours for the distance between the cars to reach 20 km.
Important Questions from Speed Distance and Time
- Two cars, P and Q, start from a point X in India at 10 AM. Car P travels North with a speed of 25 km/h and car Q travels East with a speed of 30 km/h. Car P travels continuously but car Q stops for some time after travelling for one hour. If both the cars are at the same distance from X at 11:30 AM, for how long (in minutes) did car Q stop?
In a 500 m race, P and Q have speeds in the ratio of 3: 4. Q starts the race when P has already covered 140 m.
What is the distance between P and Q (in m) when P wins the race?A vehicle is moving at a speed of 12 m/s on a level road. It applies emergency brakes and starts to skid without rolling in a straight path. The deceleration of the vehicle is constant after braking and it comes to rest at a distance of 15 m. Assuming, $g = 10$ m/s$^2$, the coefficient of kinetic friction between the tyres and road is _________ [round off to 2 decimal places]
- The distance between Delhi and Agra is 233 km. A car P started travelling from Delhi to Agra and another car Q started from Agra to Delhi along the same road 1 hour after the car P started. The two cars crossed each other 75 minutes after the car Q started. Both cars were travelling at constant speed. The speed of car P was 10 km/hr more than the speed of car Q. How many kilometers the car Q had travelled when the cars crossed each other?
Two trains started at 7AM from the same point. The first train travelled north at a speed of 80km/h and the second train travelled south at a speed of 100 km/h. The time at which they were 540 km apart is _______________ AM.
