Question 11 of 19intermediate🔧 ApplyNumerical3 marks

While practising for the snake boat race (Vallum kalli in Kerala), 100 oarsmen are rowing a boat together. Out of these, 95 row backwards to propel the boat forward. But by mistake, 5 oarsmen row in the opposite direction. If each oarsman applies a horizontal force of 200 N, what is the net force on the snake boat? (Ignore drag forces, air friction, etc.)

Correct Answer

18000 N in the forward direction

Exercise: Revise, Reflect, Refine | Q: 4 | (Chapter: 20)
For More Understanding

Explanation

The 95 oarsmen rowing backwards apply a forward force to propel the boat, while the 5 oarsmen rowing in the opposite direction apply a backward force. The total forward force is 95×20095 \times 200 N = 19000 N, and the total backward force is 5×2005 \times 200 N = 1000 N. Since these forces act in opposite directions, the magnitude of the net force is the difference between the two, and its direction is along the larger force.

Solution Steps

  1. Step 1: Total forward force = 95 oarsmen × 200 N = 19000 N

  2. Step 2: Total backward force = 5 oarsmen × 200 N = 1000 N

  3. Step 3: Net force = 19000 N - 1000 N = 18000 N (in the forward direction)

PreviousNext