6. The module of a spacecraft has a mass of 600 kg, when it is launched vertically from the surface of the Moon with its engine exerting an upward force of 2000 N. (i) Draw a diagram showing the forces acting on the module at lift-off.
(ii) What is the resultant force on the module?
(iii) Calculate the acceleration of the module during lift-off. (iv) Calculate the velocity of the module, 20 seconds after lift-off.
(v) Would the engine of the module be able to lift it off the Earth’s surface? Justify your answer in terms of the forces acting on the module.
(6) (6) (6) (6)
(9)
(vi) Why is the acceleration due to gravity on the Moon less than the acceleration due to gravity on Earth?
2009 6. Define (i) velocity, (ii) friction.
The diagram shows the forces acting on a train which was travelling horizontally. reaction
A B
A train of mass 30 000 kg started from a station and accelerated at 0.5 m s−2 to reach its top speed of 50 m s−1 and maintained this speed for 90 minutes.
As the train approached the next station the driver applied the brakes uniformly to bring the train to a stop in a distance of 500 m.
(i) Calculate how long it took the train to reach its top speed. (ii) Calculate how far it travelled at its top speed.
(4) (6)
(force due to engines)
T (5)
(vii) Suggest a reason why the module of the spacecraft when launched from the Moon does not need a streamlined shape like those that are launched from Earth.
