The figure shows a spacecraft using small thrusters to adjust its position near a satellite. In space, there is no significant air resistance. A left thrust...
Question 1 Report
The figure shows a spacecraft using small thrusters to adjust its position near a satellite. In space, there is no significant air resistance. A left thruster produces 75 N to the right. A right thruster produces 75 N to the left. A third thruster can be switched on to produce 20 N to the right. The spacecraft is initially drifting to the right at constant velocity. Mission control must predict the effect before using the third thruster.
(a) What is the resultant force when only the two 75 N thrusters operate? [1]
(b) Describe the spacecraft's motion with only these two thrusters operating. [1]
(c) Calculate the resultant force when the third thruster is also switched on. [2]
(d) Explain the change in the spacecraft's velocity after the third thruster is switched on. [2]
Answer Details
(a) The two forces are equal in size and opposite in direction, so the resultant force is \(0\text{ N}\). [1]
(b) With zero resultant force, the spacecraft continues to the right at constant velocity. [1]
(c) Taking right as positive,
\[F_\text{resultant}=75+20-75=20\text{ N}\]
The resultant force is \(20\text{ N}\) to the right. [2]
(d) The non-zero resultant force is to the right, so the spacecraft accelerates to the right. Its rightward velocity increases. [2]
Download The App On Google Playstore
Everything you need to excel in your exams
