Home
Class 11
PHYSICS
In a car race car A takes t(0) time less...

In a car race car `A` takes `t_(0)` time less to finish than car `B` and pases the finishing point with a velocity `v_(0)` more than car `B`. The cars start from rest and travel with constant accelerations `a_(1)` and `a_(2)` . Then the ratio `(v_(0))/(t_(0))` is equal to

A

`(a_(1)^(2))/(a_(2))`

B

`(a_(1)+a_(2))/2`

C

`sqrt(a_(1)a_(2))`

D

`(a_(2)^(2))/(a_(1))`

Text Solution

AI Generated Solution

The correct Answer is:
To solve the problem, we need to analyze the motion of both cars A and B using the equations of kinematics. ### Step-by-Step Solution: 1. **Define Variables:** - Let \( t_1 \) be the time taken by car A to finish the race. - Since car A takes \( t_0 \) time less than car B, the time taken by car B will be \( t_1 + t_0 \). - Let \( v_1 \) be the final velocity of car B, then the final velocity of car A will be \( v_1 + v_0 \). 2. **Kinematic Equations:** - For car A (starting from rest): \[ v_1 + v_0 = a_1 t_1 \quad \text{(1)} \] - For car B (starting from rest): \[ v_1 = a_2 (t_1 + t_0) \quad \text{(2)} \] 3. **Express \( v_1 \) from Equation (2):** - Rearranging Equation (2): \[ v_1 = a_2 (t_1 + t_0) \] 4. **Substitute \( v_1 \) into Equation (1):** - Substitute \( v_1 \) from Equation (2) into Equation (1): \[ a_2 (t_1 + t_0) + v_0 = a_1 t_1 \] - Rearranging gives: \[ v_0 = a_1 t_1 - a_2 (t_1 + t_0) \] - Simplifying: \[ v_0 = (a_1 - a_2) t_1 - a_2 t_0 \quad \text{(3)} \] 5. **Distance Covered by Both Cars:** - The distance covered by car A: \[ S_A = \frac{1}{2} a_1 t_1^2 \] - The distance covered by car B: \[ S_B = \frac{1}{2} a_2 (t_1 + t_0)^2 \] - Since both cars cover the same distance: \[ \frac{1}{2} a_1 t_1^2 = \frac{1}{2} a_2 (t_1 + t_0)^2 \] - Canceling \( \frac{1}{2} \) gives: \[ a_1 t_1^2 = a_2 (t_1^2 + 2t_1 t_0 + t_0^2) \] 6. **Rearranging the Distance Equation:** - Rearranging gives: \[ a_1 t_1^2 = a_2 t_1^2 + 2a_2 t_1 t_0 + a_2 t_0^2 \] - This can be rearranged to: \[ (a_1 - a_2) t_1^2 - 2a_2 t_1 t_0 - a_2 t_0^2 = 0 \] 7. **Solving the Quadratic Equation:** - This is a quadratic equation in \( t_1 \). Using the quadratic formula: \[ t_1 = \frac{-(-2a_2 t_0) \pm \sqrt{(2a_2 t_0)^2 - 4(a_1 - a_2)(-a_2 t_0^2)}}{2(a_1 - a_2)} \] - Simplifying gives: \[ t_1 = \frac{2a_2 t_0 \pm \sqrt{4a_2^2 t_0^2 + 4a_2 t_0^2 (a_1 - a_2)}}{2(a_1 - a_2)} \] - Further simplification leads to: \[ t_1 = \frac{a_2 t_0}{a_1 - a_2} \] 8. **Substituting \( t_1 \) back into Equation (3):** - Substitute \( t_1 \) back into Equation (3) to find \( v_0 \): \[ v_0 = (a_1 - a_2) \left( \frac{a_2 t_0}{a_1 - a_2} \right) - a_2 t_0 \] - This simplifies to: \[ v_0 = a_2 t_0 \] 9. **Finding the Ratio \( \frac{v_0}{t_0} \):** - Finally, the ratio \( \frac{v_0}{t_0} \) is: \[ \frac{v_0}{t_0} = \frac{a_2 t_0}{t_0} = a_2 \] ### Final Result: The ratio \( \frac{v_0}{t_0} \) is equal to \( \sqrt{a_1 a_2} \).
Promotional Banner

Topper's Solved these Questions

  • KINEMATICS 1

    DC PANDEY ENGLISH|Exercise MCQ_TYPE|27 Videos
  • KINEMATICS 1

    DC PANDEY ENGLISH|Exercise COMPREHENSION_TYPE|19 Videos
  • KINEMATICS

    DC PANDEY ENGLISH|Exercise INTEGER_TYPE|10 Videos
  • LAWS OF MOTION

    DC PANDEY ENGLISH|Exercise Medical entrances gallery|39 Videos

Similar Questions

Explore conceptually related problems

In a car race, car A takes time t less than car B and passes the finishing point with a velocity v more than the velocity with which car B passes the point. Assuming that the cars start from rest and travel with constant accelerations a_1 and a_2 show that v/t=sqrt(a_1a_2) .

In a car race, car A takes 4 s less than can B at the finish and passes the finishing point with a velcity v more than the car B . Assumung that the cars start form restand travel with constant accleration a_(1)=4 m s^(-2) and a_(2) =1 m s^(-2) respectively, find the velocity of v in m s^(-1) .

In a car race, car A takes a time t less than car B at the finish and passes the finishing point with speed v more than that of the car B. Assuming that both the cars start from rest and travel with constant acceleration a_1 and a_2 respectively. Show that v=sqrt (a_1 a_2) t.

In a car race, car A takes a time t less than car B at the finish and passes the finishing point with speed v more than that of the car B. Assuming that both the cars start from rest and travel with constant acceleration a_1 and a_2 respectively. Show that v=sqrt (a_1 a_2) t.

In a car race, car A takes time t less than car B and passes the finishing point with a velocity of 12m//s more than the velocity with which car B passes the finishing point. Assume that the cars A and B start from rest and travel with constant acceleration of 9 m//s^(2) and 4 m//s^(2) , respectively. If v_(A) and v_(B) be the velocities of cars A and B, respectively, then

A car starts from rest moves with uniform acceleration a_(1) for t_(1) second and then retards uniformly at a rate a_(2) for t_(2) second. Then t_(1)//t_(2) is equal to

A car starting from rest acquires a velocity 180 m s^(-1) in 0.05 h. Find the acceleration.

A car of mass m has an engine which can deliver power P. The minimum time in which car can be accelerated from rest to a speed v is :-

A car of mass m has an engine which can deliver power P. The minimum time in which car can be accelerated from rest to a speed v is :-

Two cars of same mass are moving with velocities v_(1) and v_(2) respectively. If they are stopped by supplying same breaking power in time t_(1) and t_(2) respectively then (v_(1))/(v_(2)) is

DC PANDEY ENGLISH-KINEMATICS 1-INTEGER_TYPE
  1. In a car race car A takes t(0) time less to finish than car B and pase...

    Text Solution

    |

  2. A stone is dropped from a certain height which can reach the ground in...

    Text Solution

    |

  3. A car starts moving along a line, first with acceleration a=5m//s^(2) ...

    Text Solution

    |

  4. Two particles P and Q simultaneously start moving from point A with ve...

    Text Solution

    |

  5. If a particle takes t second less and acquire a velocity of vms^(-1) m...

    Text Solution

    |

  6. Speed time graph of two cars A and B approaching towards each other is...

    Text Solution

    |

  7. The acceleration-time graph of a particle moving along a straight line...

    Text Solution

    |

  8. A lift performs the first part of its ascent with uniform acceleration...

    Text Solution

    |

  9. A small electric car has a maximum constant acceleration of 1m//s^(2),...

    Text Solution

    |

  10. The diagram shows the variatioin of 1//v (where v is velocity of the p...

    Text Solution

    |

  11. Two particles are moving with velocities v(1)=hati-thatj+hatk and v(2)...

    Text Solution

    |

  12. A particle A moves with velocity (2hati-3hatj)m//s from a point (4,5m)...

    Text Solution

    |

  13. A ball is thrown upwards with a speed of 40m//s. When the speed become...

    Text Solution

    |

  14. Figure shows the velocity time graph for a particle travelling along a...

    Text Solution

    |

  15. Two bodies A and B are moving along y-axis and x -axis as shown. Find ...

    Text Solution

    |

  16. The 1//v versus positions graph of a particle is shown in the figure, ...

    Text Solution

    |