physics
posted by Anonymous
A rocket engine on a spacecraft of total mass 10,000kg ejected 1.4kg of hot gases every second at an average discontinuous speed of 240ms1.
1 What was the force on the spacecraft?
2 What was the acceleration of the spacecraft?
3If the engines were used for 30's, what was the impulse given to the spacecraft?
4 What was the change of velocity?
please help I've been thinking of how to solve it for an hour

Damon
force = rate of change of momentum
change of momentum of vehicle + change of momentum of fuel = 0
in one second:
10,000 (change of vehicle speed) = 1.4*240 = 336 kg m/s
so
change of vehicle momentum per second =336 kg m/s^2 = Force (answer #1)
acceleration = change of vehicle speed per second = 336*10^4 =3.36*10^2 m/s^2
impulse = change of momentum in 30 seconds = Force * 30
change of velocity = change of momentum / mass 
anonymus
so for change of momentum = 336 divided by 10,000? @Damon
Respond to this Question
Similar Questions

physics
Model rocket engines are sized by thrust, thrust duration, and total impulse, among other characteristics. A size C5 model rocket engine has an average thrust of 5.26 N, a fuel mass of 12.7 g, and an initial mass of 25.5 g. The duration … 
physics
A 200.0 kg astronaut and equipment move with a velocity of 2.00 m/s toward an orbiting spacecraft. The astronaut will fire a 100.0 N rocket backpack to stop his motion relative to the spacecraft. (a) What acceleration is attained by … 
Physics
A spacecraft is traveling with a velocity of v0x = 5040 m/s along the +x direction. Two engines are turned on for a time of 801 s. One engine gives the spacecraft an acceleration in the +x direction of ax = 1.04 m/s2, while the other … 
physics
A spacecraft of mass is first brought into an orbit around the earth. The earth (together with the spacecraft) orbits the sun in a near circular orbit with radius ( is the mean distance between the earth and the sun; it is about 150 … 
Physics
The Apollo spacecrafts were launched toward the moon using the Saturn rocket, the most powerful rocket available. Each rocket had five engines producing a total of 3.34 x 10 to the 7thX of force to launch the 2.77 x 10 to the 6 kg … 
physics
A spacecraft is traveling with a velocity of v0x = 5690 m/s along the +x direction. Two engines are turned on for a time of 845 s. One engine gives the spacecraft an acceleration in the +x direction of ax = 1.35 m/s2, while the other … 
physics
A Titan IV rocket has put your spacecraft in a circular orbit around Earth at an altitude of 230 km. Calculate the force due to gravitational attraction between the Earth and the spacecraft in N if the mass of the spacecraft is 2300 … 
Physics
A rocket has put your spacecraft in a circular orbit around Earth at an altitude of 350 km. Calculate the force due to gravitational between the Earth and the spacecraft in N if the mass of the spacecraft is 2450 kg. 
Physics
The mass of a spacecraft is about 480 kg. An engine designed to increase the speed of the spacecraft while in outer space provides 0.09 N thrust at maximum power. By how much does the engine cause the craft's speed to change in 1 week … 
Physics
A 70.0kg astronaut pushes to the left on a spacecraft with a force in "gravityfree" space. The spacecraft has a total mass of 1.0 × 104 kg. During the push, the astronaut accelerates to the right with an acceleration of 0.36 …