A 50-kilogram box is initially at rest. The box is pulled along the ground with a force of 200 newtons at an angle of 30° to the horizontal. The box experiences a resistive force of    newtons, where is the normal force, as shown in the diagram.
 
Take the acceleration due to gravity to be 10m/s².
 

1. By resolving the forces vertically, show that  .   (2 marks)
   

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2. Show that the net force horizontally is approximately 53.2 newtons.  (2 marks)
   

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3. Find the velocity of the box after the first three seconds.  (2 marks)
   

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