Acceleration is calculated using the formula 𝑎=Δ𝑣/𝑡 a= 5s 20m/s−0m/s=4m/s 2 /2 .
From Newton’s Second Law, 𝐹=𝑚a, rearrange to 𝑎=𝐹/𝑚. a= 50N/ 10kg =5m/s 2. . .
In a perfectly elastic collision, momentum is conserved. Initial momentum: Solve for v: 6=2+v,v=4m/s.
Use the equation for free fall, v= 2gh: v= 2⋅9.8⋅20= 392 ≈28m/s.
The potential energy at the top is converted into kinetic energy at the bottom: mgh= 1/2 mv 2 ⟹v= 2gh .Substitute: 𝑣=2⋅9.8⋅5=98≈10m/s.
