Home
Class 11
PHYSICS
A rocket is going upward with accelerati...

A rocket is going upward with acceleration motion. A man sitting in it feels his weight increased 5 times his own weight. If the mass of the rocket including that of the man is `1.0xx10^(4)kg` , how much force is being applied by rocket engine? (Take `g = 10 ms^(-2))`.

A

`5xx10^(4)N`

B

`5xx10^(5)N`

C

`5xx10^(8)N`

D

`2xx10^(4)N`

Text Solution

AI Generated Solution

The correct Answer is:
To solve the problem, we need to analyze the forces acting on the rocket and the man inside it. ### Step 1: Understand the Forces Acting on the Rocket When the rocket is accelerating upwards, the man inside feels an increased weight due to the acceleration of the rocket. The apparent weight \( W' \) that the man feels is given by: \[ W' = m(g + A) \] where: - \( m \) is the mass of the man, - \( g \) is the acceleration due to gravity (10 m/s²), - \( A \) is the upward acceleration of the rocket. ### Step 2: Relate the Increased Weight to the Original Weight According to the problem, the man feels that his weight has increased 5 times his original weight. Therefore, we can write: \[ W' = 5mg \] ### Step 3: Set Up the Equation From the two equations we have: \[ m(g + A) = 5mg \] ### Step 4: Simplify the Equation We can simplify the equation by dividing both sides by \( m \) (assuming \( m \neq 0 \)): \[ g + A = 5g \] ### Step 5: Solve for the Acceleration \( A \) Now, we can isolate \( A \): \[ A = 5g - g = 4g \] Substituting \( g = 10 \, \text{m/s}^2 \): \[ A = 4 \times 10 = 40 \, \text{m/s}^2 \] ### Step 6: Calculate the Total Force Exerted by the Rocket Engine The total force \( F \) exerted by the rocket engine must overcome both the gravitational force and provide the upward acceleration. The total force can be calculated using Newton's second law: \[ F = (m + M)g + (m + M)A \] Where: - \( M \) is the mass of the rocket (including the man), given as \( 1.0 \times 10^4 \, \text{kg} \). ### Step 7: Substitute Values into the Force Equation We can substitute \( g \) and \( A \) into the equation: \[ F = (1.0 \times 10^4)(10) + (1.0 \times 10^4)(40) \] Calculating each part: 1. Gravitational force: \( (1.0 \times 10^4)(10) = 1.0 \times 10^5 \, \text{N} \) 2. Force due to acceleration: \( (1.0 \times 10^4)(40) = 4.0 \times 10^5 \, \text{N} \) ### Step 8: Calculate Total Force Now, add the two forces together: \[ F = 1.0 \times 10^5 + 4.0 \times 10^5 = 5.0 \times 10^5 \, \text{N} \] ### Final Answer The force being applied by the rocket engine is \( 5.0 \times 10^5 \, \text{N} \). ---

To solve the problem, we need to analyze the forces acting on the rocket and the man inside it. ### Step 1: Understand the Forces Acting on the Rocket When the rocket is accelerating upwards, the man inside feels an increased weight due to the acceleration of the rocket. The apparent weight \( W' \) that the man feels is given by: \[ W' = m(g + A) \] ...
Doubtnut Promotions Banner Mobile Dark
|

Topper's Solved these Questions

  • NEWTONS LAWS OF MOTION

    A2Z|Exercise AIIMS Questions|26 Videos
  • MOTION IN TWO DIMENSION

    A2Z|Exercise Chapter Test|29 Videos
  • OSCILLATION AND SIMPLE HARMONIC MOTION

    A2Z|Exercise Chapter Test|29 Videos

Similar Questions

Explore conceptually related problems

A rocket is going upwards with accelerated motion A man sitting in the rocket feels his weight becomes 5 times If mass of rocket inculding that of the man is 0.1 xx 10^(4)kg how much force is beigh applied by rocket engine? Take g = 10m//s^(2) .

A rocket with a lift mass of 10,000 kg is blasted upwards with an acceleration of 10ms^(-2) . Calculate the initial thrust of the blast

Knowledge Check

  • A rocket with a lift-off mass 3.5xx10^4 kg is blasted upwards with an initial acceleration of 10m//s^2 . Then the initial thrust of the blast is

    A
    (a) `3.5xx10^5N`
    B
    (b) `7.0xx10^5N`
    C
    (c) `14.0xx10^5N`
    D
    (d) `1.75xx10^5N`
  • The person o( mass 50 kg slands on a weighing scale on a lift. If the lift is ascending upwards with a uniform acceleration of 9ms^(-2) , what would be the reading of the weighting scale? ("Take g"=10ms^(-2))

    A
    50kg
    B
    60kg
    C
    96kg
    D
    176kg
  • Similar Questions

    Explore conceptually related problems

    How many protons weight 5kg? The mass of a proton is 1.67xx10^(-27)kg .

    A man fell into a manhole of depth 1 m. If his mass is 65 kg, then what should be the work done by him to come out of it (Take g = 10 ms^(-2) ).

    A man of weight 50kg carries an object to a height of 20m in a time of 10s .The power used by the man in this process is 2000W then find the weight of the object carried by the man take g=10ms^(-2)

    A person in an elevator accelerating upwards with an acceleration of 2ms^(-2) , tosses a coin vertically upwards with a speed of 20 ms^(-1) . After how much time will the coin fall back into his hand ? (g = 10 ms^(-2) )

    The mass of a rocket is 500 kg and the relative velocity of the gases ejecting from it is 250 m/s with respect to the rocket. The rate of burning of the fuel in order to give the rocket an initial acceleration 20 m//s^(2) in the vertically upward direction g = 10 m/s^(2) , will be -

    A rocket of initial mass m ( including fuel) ejects mass at a constant rate of 25 kg/s with a speed 60 m/s relative to the rocket. If the acceleration of the rocket 3.5 minutes after the firing is 2m//s^(2) . What is the initial mass of the rocket ? [Neglect gravity] Express your answer in unit of 10^(3) kg