Home
Class 12
PHYSICS
An unloaded bus can be stopped by applyi...

An unloaded bus can be stopped by applying brakies on straight road after covering a distance x. Suppose, the passenger add `50%` of its weight as the load and the braking force remains unchanged, how far will the bus go after the application of the brakes ?(Velocity of bus in both case is same) (Consider negligible friction):-

A

Zero

B

1.5x

C

2x

D

2.5x

Text Solution

AI Generated Solution

The correct Answer is:
To solve the problem, we need to analyze the situation using the principles of physics, specifically the equations of motion and Newton's second law. ### Step-by-Step Solution: 1. **Understand the Initial Conditions**: - Let the mass of the unloaded bus be \( m \). - The bus can stop after covering a distance \( x \) when it is unloaded. - The initial velocity of the bus is \( u \) and the final velocity when it stops is \( 0 \). 2. **Apply the Equation of Motion**: - We can use the equation of motion: \[ v^2 - u^2 = 2as \] - Here, \( v = 0 \) (final velocity), \( u \) is the initial velocity, \( a \) is the acceleration (which will be negative since it is deceleration), and \( s \) is the distance \( x \). 3. **Express Acceleration in Terms of Force**: - According to Newton's second law, the acceleration \( a \) can be expressed as: \[ a = \frac{F}{m} \] - Where \( F \) is the braking force applied, and \( m \) is the mass of the bus. 4. **Substituting the Values**: - Substitute \( v = 0 \) and \( a = \frac{F}{m} \) into the equation of motion: \[ 0 - u^2 = 2 \left(\frac{F}{m}\right)x \] - Rearranging gives: \[ -mu^2 = 2Fx \] 5. **Consider the Loaded Bus**: - When passengers add a load of \( 50\% \) of the bus's weight, the new mass \( m' \) becomes: \[ m' = m + 0.5m = 1.5m \] - The braking force \( F \) remains unchanged. 6. **Calculate the New Stopping Distance**: - Let \( x' \) be the distance the loaded bus will travel before stopping. Using the same logic: \[ -m'u^2 = 2Fx' \] - Substitute \( m' = 1.5m \): \[ -1.5mu^2 = 2Fx' \] 7. **Relate the Two Distances**: - We can relate the two equations: \[ -mu^2 = 2Fx \quad \text{(from the unloaded bus)} \] - Therefore, substituting for \( F \) from the first equation into the second: \[ -1.5mu^2 = 2\left(-\frac{mu^2}{2x}\right)x' \] - This simplifies to: \[ 1.5x = x' \] 8. **Final Result**: - Thus, the distance \( x' \) that the loaded bus will travel before stopping is: \[ x' = 1.5x \] ### Conclusion: The bus will cover a distance of \( 1.5x \) after the application of the brakes when loaded with passengers.
Promotional Banner

Topper's Solved these Questions

  • WORK, ENERGY AND POWER

    AAKASH INSTITUTE ENGLISH|Exercise Assignment (SECTION - B)|35 Videos
  • WORK, ENERGY AND POWER

    AAKASH INSTITUTE ENGLISH|Exercise Assignment (SECTION - C)|80 Videos
  • WORK, ENERGY AND POWER

    AAKASH INSTITUTE ENGLISH|Exercise EXERCISE|37 Videos
  • WAVES

    AAKASH INSTITUTE ENGLISH|Exercise ASSIGNMENT ( SECTION-D ( Assertion - Reason Type Questions ))|12 Videos

Similar Questions

Explore conceptually related problems

An unloaded bus can be stopped by applying brakes on straight road after covering distance x. Suppose. The passengers add 40% of its weight as the load the braking force remains same. How far will the bus go after the application of the breakes? (Velocity of bus is same in both the cases)

A car moving with speed v on a straight road can be stopped with in distance d on applying brakes. If same car is moving with speed 3v and brakes provide half retardation, then car will stop after travelling distance

A bus is moving on a straight road towards north with a uniform speed of 50 km//hour turns left through 90^(@) . If the speed remains unchanged after turning, the increase in the velocity of bus in the turning process is

The driver of a car moving with a speed of 10 ms^(-1) sees a red light ahead, applies brakes and stops after covering 10 m distance. If the same car were moving with a speed of 20 ms^(-1) the same driver would have stopped the car after covering 30 m distance. Within what distance the car can be stopped if traveling with a velocity of 15 ms^(-1) Assume the same reaction time and the same deceleration in each case

A bus can be stopped by applying a retarding force F when it is moving with speed v on a level road. The distance covered by it before coming to rest is s . If the load of the bus increase by 50% because of passengers, for the same speed and same retarding force, the distance covered by the bus to come to rest shall be

The word fluid means a substance having particles which readily of its magnitude (a small shear stress, which may appear to be of negligible will cause deformation in the fluid). Fluids are charactrised by such properties as density. Specific weight, specific gravity, viscosity etc. Density of a substance is defined as mass per unit volume and it is denoted by. The specific gravity represents a numerical ratio of two densities, and water is commonly taken as a reference substance. Specific gravity of a substance in written as the ratio of density of substance to the density of water. Specific weight represents the force exerted by gravity on a unit volume of fluid. It is related to the density as the product of density of a fluid and acceleration due to gravity. Viscosity is the most important and is recognized as the only single property which influences the fluid motion to a great extent. The viscosity is the property by virtue of which a fluid offers resistance to deformation under the influenece if shear force. The force between the layers opposing relative motion between them are known as forces of viscosity. When a boat moves slowly on the river remains at rest. Velocities of different layers are different. Let v be the velocity of the level at a distance y from the bed and V+dv be the velocity at a distance y+dy . The velocity differs by dv in going through a distance by perpendicular to it. The quantity (dv)/(dy) is called velocity gradient. The force of viscosity between two layers of a fluid is proportional to velocity gradient and Area of the layer. F prop A & F prop (dv)/(dy) F= -etaA(dv)/(dy) ( -ve sign shown the force is frictional in nature and opposes relative motion. eta coefficient of dynamic viscosity Shear stress (F)/(A)= -eta(dv)/(dy) and simultaneously kinematic viscosity is defined as the dynamic viscosity divided by the density. If is denoted as v . The viscosity of a fluid depends upon its intermolecular structure. In gases, the molecules are widely spaced resulting in a negligible intermolecular cohesion, while in liquids the molecules being very close to each other, the cohesion is much larger with the increases of temperature, the cohesive force decreases rapidly resulting in the decreases of viscosity. In case of gases, the viscosity is mainly due to transfer of molecular momentum in the transerve direction brought about by the molecular agitation. Molecular agitation increases with rise in temperature. Thus we conclude that viscosity of a fluid may thus be considered to be composed of two parts, first due to intermolecuar cohesion and second due to transfer of molecular momentum. If the velocity profile is given by v=(2)/(3)y-y^(2)v is velocity in m//sec y is in meter above the bad. Determine shear stress at y=0.15m , & eta=0.863 Ns//m^(2)

The word fluid means a substance having particles which readily of its magnitude (a small shear stress, which may appear to be of negligible will cause deformation in the fluid). Fluids are charactrised by such properties as density. Specific weight, specific gravity, viscosity etc. Density of a substance is defined as mass per unit volume and it is denoted by. The specific gravity represents a numerical ratio of two densities, and water is commonly taken as a reference substance. Specific gravity of a substance in written as the ratio of density of substance to the density of water. Specific weight represents the force exerted by gravity on a unit volume of fluid. It is related to the density as the product of density of a fluid and acceleration due to gravity. Viscosity is the most important and is recognized as the only single property which influences the fluid motion to a great extent. The viscosity is the property by virtue of which a fluid offers resistance to deformation under the influenece if shear force. The force between the layers opposing relative motion between them are known as forces of viscosity. When a boat moves slowly on the river remains at rest. Velocities of different layers are different. Let v be the velocity of the level at a distance y from the bed and V+dv be the velocity at a distance y+dy . The velocity differs by dv in going through a distance by perpendicular to it. The quantity (dv)/(dy) is called velocity gradient. The force of viscosity between two layers of a fluid is proportional to velocity gradient and Area of the layer. F prop A & F prop (dv)/(dy) F= -etaA(dv)/(dy) ( -ve sign shown the force is frictional in nature and opposes relative motion. eta coefficient of dynamic viscosity Shear stress (F)/(A)= -eta(dv)/(dy) and simultaneously kinematic viscosity is defined as the dynamic viscosity divided by the density. If is denoted as v . The viscosity of a fluid depends upon its intermolecular structure. In gases, the molecules are widely spaced resulting in a negligible intermolecular cohesion, while in liquids the molecules being very close to each other, the cohesion is much larger with the increases of temperature, the cohesive force decreases rapidly resulting in the decreases of viscosity. In case of gases, the viscosity is mainly due to transfer of molecular momentum in the transerve direction brought about by the molecular agitation. Molecular agitation increases with rise in temperature. Thus we conclude that viscosity of a fluid may thus be considered to be composed of two parts, first due to intermolecuar cohesion and second due to transfer of molecular momentum. Viscosity of liquids

Ram and Ali have been fast friends since childhood. Ali neglected studies and now has no means to earn money other than a channel whereas Ram has become an engineer. Now both are working in the same factory. Ali uses camel to transport the load within the factory. Due to low salary and degradation in health of camel, Ali becomes worried and meets his friend Ram and discusses his problems. Ram collected some data and with some assumptions concluded the following: i. The load used in each trip is 1000kg and has friction coefficient mu_k=0.1 and mu_s=0.2 . ii. Mass of camel is 500kg . iii. Load is accelerated for first 50m with constant acceleration, then it is pulled at a constant speed of 5ms^-1 for 2km and at last stopped with constant retardation in 50m . iv. From biological data, the rate of consumption of energy of camel can be expressed as P=18xx10^3v+10^4Js^-1 where P is the power and v is the velocity of the camel. After calculations on different issues, Ram suggested proper food, speed of camel, etc. to his friend. For the welfare of Ali, Ram wrote a letter to the management to increase his salary. (Assuming that the camel exerts a horizontal force on the load): The ratio of the energy consumed by the camel during uniform motion for the two cases when it moves with speed 5ms^-1 to the case when it moves with 10ms^-1

Ram and Ali have been fast friends since childhood. Ali neglected studies and now has no means to earn money other than a channel whereas Ram has become an engineer. Now both are working in the same factory. Ali uses camel to transport the load within the factory. Due to low salary and degradation in health of camel, Ali becomes worried and meets his friend Ram and discusses his problems. Ram collected some data and with some assumptions concluded the following: i. The load used in each trip is 1000kg and has friction coefficient mu_k=0.1 and mu_s=0.2 . ii. Mass of camel is 500kg . iii. Load is accelerated for first 50m with constant acceleration, then it is pulled at a constant speed of 5ms^-1 for 2km and at last stopped with constant retardation in 50m . iv. From biological data, the rate of consumption of energy of camel can be expressed as P=18xx10^3v+10^4Js^-1 where P is the power and v is the velocity of the camel. After calculations on different issues, Ram suggested proper food, speed of camel, etc. to his friend. For the welfare of Ali, Ram wrote a letter to the management to increase his salary. (Assuming that the camel exerts a horizontal force on the load): Maximum power transmitted by the camel to load is

Ram and Ali have been fast friends since childhood. Ali neglected studies and now has no means to earn money other than a channel whereas Ram has become an engineer. Now both are working in the same factory. Ali uses camel to transport the load within the factory. Due to low salary and degradation in health of camel, Ali becomes worried and meets his friend Ram and discusses his problems. Ram collected some data and with some assumptions concluded the following: i. The load used in each trip is 1000kg and has friction coefficient mu_k=0.1 and mu_s=0.2 . ii. Mass of camel is 500kg . iii. Load is accelerated for first 50m with constant acceleration, then it is pulled at a constant speed of 5ms^-1 for 2km and at last stopped with constant retardation in 50m . iv. From biological data, the rate of consumption of energy of camel can be expressed as P=18xx10^3v+10^4Js^-1 where P is the power and v is the velocity of the camel. After calculations on different issues, Ram suggested proper food, speed of camel, etc. to his friend. For the welfare of Ali, Ram wrote a letter to the management to increase his salary. (Assuming that the camel exerts a horizontal force on the load): Sign of work done by the camel on the load during parts of motion, accelerated motion, uniform motion and retarded motion, respectively are

AAKASH INSTITUTE ENGLISH-WORK, ENERGY AND POWER-Assignment (SECTION - A)
  1. For a particle moving under the action of a variable force, kinetic en...

    Text Solution

    |

  2. A particle of mass 1 kg is subjected to a force which varies with dist...

    Text Solution

    |

  3. An unloaded bus can be stopped by applying brakies on straight road af...

    Text Solution

    |

  4. The power of water pump is 4 kW. If g=10 ms^(-2), the amount of water ...

    Text Solution

    |

  5. A particle moves with the velocity vecv=(5hati+2hatj-hatk)ms^(-1) unde...

    Text Solution

    |

  6. A body is projected from ground obliquely. During downward motion, pow...

    Text Solution

    |

  7. The blades of a windmill sweep out a circle of area A. If the wind flo...

    Text Solution

    |

  8. A body of mass m, accelerates uniformly from rest to V(1) in time t(1)...

    Text Solution

    |

  9. The power of a pump, which can pump 500 kg of water to height 100 m in...

    Text Solution

    |

  10. A pump is used to pump a liquid of density rho continuously through a ...

    Text Solution

    |

  11. A car of mass m has an engine which can deliver power P. The minimum t...

    Text Solution

    |

  12. Water from a stream is falling on the blades of a turbine at the rate ...

    Text Solution

    |

  13. On a particle placed at origin a variable force F=-ax(where a is a pos...

    Text Solution

    |

  14. The variation of potential energy U of a system is shown in figure. Th...

    Text Solution

    |

  15. The variation of potential energy U of a body moving along x - axis va...

    Text Solution

    |

  16. A particle of mass 200 g is moving in a circle of radius 2 m. The part...

    Text Solution

    |

  17. A particle of mass 200 g , is whirled into a vertical circle of radius...

    Text Solution

    |

  18. A stone of mass 1kg is tied with a string and it is whirled in a verti...

    Text Solution

    |

  19. An object of mass 80 kg moving with velocity 2ms^(-1) hit by collides ...

    Text Solution

    |

  20. A ball of mass m moving with velocity v collides head-on which the sec...

    Text Solution

    |