Home
Class 11
PHYSICS
A body is projected up such that its pos...

A body is projected up such that its position vector varies with time as `vecr={3thati+(4t-5t^(2))hatj} m`. Here `t` is in second.The time when its `y`-coordinate is zero is

A

`3 s`

B

`1 s`

C

`0.8 s`

D

`1.25 s`

Text Solution

Verified by Experts

The correct Answer is:
C
`4t-5t^(2)=0`
Promotional Banner

Topper's Solved these Questions

  • MOTION IN A PLANE

    NARAYNA|Exercise Level-I (H.W)|41 Videos

  • MECHANICAL PROPERTIES OF SOLIDS

    NARAYNA|Exercise LEVEL-II (H.W)|24 Videos

  • MOTION IN A STRAIGHT LINE

    NARAYNA|Exercise Level 2 H.W|29 Videos

Similar Questions

Explore conceptually related problems

A body is projected up such that its position vector varies with time as r = { 3thati + (4 t - 5t^2)hatj} m. Here, t is in seconds. Find the time and x-coordinate of particle when its y-coordinate is zero.

A body is projected up such that its position vector varies with time as barr=6t hati+(8t-5t^(2))hatj. Find the (a) initial velocity (b) time of fight.

An object moves along x-axis such that its position varies with time according to the relation x=50t-5t^(2) Here, x is in meters and time is in seconds. Find the displacement and distance travelled for the time interval t = 0 to t = 6 s.

A particle moves in space such that its position vector varies as vec(r)=2thati+3t^(2)hatj . If mass of particle is 2 kg then angular momentum of particle about origin at t=2 sec is

A body moves along x-axis such that its displacement varies with time as given, x=7 + 3t + 5t^2 . The average velocity during 3rd second is

The position of a particel is expressed as vecr = ( 4t^(2)hati + 2thatj) m. where t is time in second. Find the acceleration of the particle.

A particle moves in xy-plane. The position vector of particle at any time is vecr={(2t)hati+(2t^(2))hatj}m. The rate of change of theta at time t = 2 second. ( where 0 is the angle which its velocity vector makes with positive x-axis) is :

The position of an object is given by vecr= ( 9 thati + 4t^(3)hatj) m. find its velocity at time t= 1s.

The position vector of a particle is given by vecr=(3t^(2)hati+4t^(2)hatj+7hatk)m at a given time t .The net displacement of the particle after 10 s is

NARAYNA-MOTION IN A PLANE-Level-II(H.W)
  1. A and B are two pegs separated by 13 cm.A body of 169 kgwt is suspende...

    Text Solution

    |

  2. Two particles having position vectors vecr(1)=(3veci+5 vecj)m and vec...

    Text Solution

    |

  3. A body is projected up such that its position vector varies with time ...

    Text Solution

    |

  4. The position of a particle is given by vecr=3tveci-2t^(2)hatj+4hatk m ...

    Text Solution

    |

  5. A particle starts from origin at t=0 with a constant velocity 5hati m/...

    Text Solution

    |

  6. When two bodies approach each other with the different speeds, the dis...

    Text Solution

    |

  7. An aeroplane is flying with the velocity of V(1)=800kmph relative to t...

    Text Solution

    |

  8. A boat takes 4 hr upstream and 2 hr down the stream for covering the s...

    Text Solution

    |

  9. The width of a river is 2sqrt3km.A boat is rowed in direction perpendi...

    Text Solution

    |

  10. Person aiming to reach the exactly opposite point on the bank of a str...

    Text Solution

    |

  11. A particle projected from the level ground just clears in its ascent a...

    Text Solution

    |

  12. A stone is projected with a velocity 20sqrt2 m//s at an angle of 45^(@...

    Text Solution

    |

  13. A ball is thrown with velocity 8 ms^(-1) making an angle 60^(@) with t...

    Text Solution

    |

  14. The range of a projectile launched at an angle of 15^(@) with horizont...

    Text Solution

    |

  15. A body is projected obliquely from the ground such that its horizontal...

    Text Solution

    |

  16. A projectile is thrown at angle beta with vertical.It reaches a maximu...

    Text Solution

    |

  17. The maximum height attained by a projectile is increased by 5%. Keepin...

    Text Solution

    |

  18. A gardener wants to wet the garden without moving from his place with ...

    Text Solution

    |

  19. A particle is projected with speed u at angle theta to the horizontal....

    Text Solution

    |

  20. From the top of a tower of height 78.4 m two stones are projected hori...

    Text Solution

    |