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
- A car is moving on a horizontal surface in a straight line with a constant velocity of 3 m/s. A ball is thrown vertically upwards at time $t = 0$ from the top of the moving car with a velocity of 20 m/s. The acceleration due to gravity is 10 m/s$^2$.
At what value(s) of time $t$ in second(s), the ball is at a height of 15 m from the top of the moving car? - Velocity of an object fired directly in upward direction is given by $V = 80 – 32 \ t$, where $t$ (time) is in seconds. When will the velocity be between 32 m/sec and 64 m/sec?
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?- An automobile travels from city A to city B and returns to city A by the same route. The speed of the vehicle during the onward and return journeys were constant at 60 km/h and 90 km/h, respectively. What is the average speed in km/h for the entire journey?
- Trucks (10 m long) and cars (5 m long) go on a single lane bridge. There must be a gap of at least 20 m after each truck and a gap of at least 15 m after each car. Trucks and cars travel at a speed of 36 km/h. If cars and trucks go alternately, what is the maximum number of vehicles that can use the bridge in one hour?
