A body is thrown vertically upward at 100 m/s and travels 5 m in the last second of its upward journey. If projected at 200 m/s, find the distance (m) travelled in 'the second' mentioned in the source. Use g = 10 m/s².
Physics · Mixed Chapter
JEE Main Practice

Question

A body is thrown vertically upward at 100 m/s and travels 5 m in the last second of its upward journey. If projected at 200 m/s, find the distance (m) travelled in 'the second' mentioned in the source. Use g = 10 m/s².

Physics · Mixed Chapter

G1 Physics · Accepted Answer

Step 1: The displacement during the final 1 s of ascent is ½g(1)² = 5 m, irrespective of initial launch speed. Step 2: For u = 200 m/s, ascent time is u/g = 20 s. During 19–20 s, speed decreases from 10 m/s to 0. Step 3: Distance = average speed ×1 s = (10+0)/2 = 5 m. Step 4: The source omits which second for the new launch; this answer assumes the last second of upward travel.