Given, height of cliff, H=490m Initial speed along X-axis, ux=15ms−1 and initial speed along Y-axis, uy=0ms−1 Acceleration due to gravity g=10ms−2 As we know that, for motion along Y-axis, vy2−uy2=2‌gH ⇒vy=√2gH=√2×10×490=70√2ms−1=99ms−1