Question

rocket has a mass of 2 x 104 kg, of which half is fuel. Assume that fuel is burnt at constant rate and there is a constant thrust of 5 x 106 N. Neglecting air resistance and any variation in acceleration due to gravity. The acceleration at the instant when the whole fuel is consumed will be​

Answer 1

Answer:

490 m s‐²

Explanation:

When the fuel has been completly exhausted , remaining mass of rocket

F = upthrust - weight (m'' g)

5×106−104×10=49×105

∴ Acceleration = Fm=49×105104=490m/s2 .

Answer 2

Given:

Mass of rocket = 2*10⁴ kg

Constant thrust = 5*10⁶ N

To find:

The acceleration at the instant when the whole fuel is consumed.

Solution:

If the whole fuel is consumed then only the mass of the rocket will amount to its weight.

Therefore m= 10⁴ kg

We know that the thrust force acts in the direction of motion of rocket while the acceleration acts in the opposite direction, the equation will be :

m*a = Thrust - m*g

10⁴*a = 5*10⁶ - 10⁴*10

10⁴*a = 49*10⁵

a = 49*10⁵/ 10⁴

a = 490 m/s²

Therefore the acceleration at that instant will be 490 m/s².