A body of mass 2kg falls freely from rest through a height of 50m and come to rest having penetrated 5.0cm of sand. calculate the velocity and time taken and the average force
To calculate the velocity and time taken for the body to come to rest, we can use the equations of motion.
1. First, let's calculate the final velocity using the equation v^2 = u^2 + 2as, where:
- v is the final velocity (which is 0 since the body comes to rest)
- u is the initial velocity (0 since the body starts from rest)
- a is the acceleration (which we need to calculate)
- s is the distance travelled (50m)
Rearranging the equation, we get 0 = 0 + 2a * 50m. Solving for a, we find a = - (0 / (2*50)) = 0 m/s^2. (Note that acceleration is negative here because the body is slowing down.)
2. Next, let's calculate the time taken using the equation v = u + at. Since v = 0 and u = 0, we have 0 = 0 + 0 * t. This equation implies that it took the body 0 seconds to come to rest (since there is no time required for the body to stop falling).
3. Finally, let's calculate the average force acting on the body. We can use Newton's second law, which states that force (F) is equal to mass (m) multiplied by acceleration (a). Given that the mass of the body is 2 kg and the acceleration is 0 m/s^2, the average force (F) acting on the body is F = m * a = 2 kg * 0 m/s^2 = 0 N.
Thus, the velocity is 0 m/s, the time taken is 0 seconds, and the average force is 0 N.