Consider a jet of water striking a vertical wall horizontally a speed of v. After hitting the wall, the water moves along the wall. If the area of cross-section of the water jet is S, Find the force that it applies on the wall. Take the mass density of water to be p.
THUADI PHEN DA CHOLA . NALE TERI MA MERE KIOL RAATI AYI SI QUESTION SAMJAN LIYE SARA SAMJATA. TUNVI AJI JE ANA HOYE GA . HARAMKHOR SALEY FREE DIYAN SITAN CHALIYAN HOIYAN NE PHEN DE TAKKE SALEY
To find the force that the water applies on the wall, we need to consider the change in momentum of the water jet before and after hitting the wall.
The initial momentum of the water jet before hitting the wall can be calculated using the formula:
Initial momentum = mass x velocity
The mass of the water jet can be calculated using the formula:
Mass = mass density x volume
The volume of the water jet can be calculated using the formula:
Volume = area x length
Therefore, the initial momentum of the water jet can be calculated as:
Initial momentum = (mass density x volume) x velocity
After hitting the wall, the water moves along the wall, so its velocity changes to zero. Therefore, the final momentum of the water jet is zero.
The change in momentum can be calculated as:
Change in momentum = Final momentum - Initial momentum
= 0 - (mass density x volume x velocity)
Using the equation for volume, we can substitute it in the formula for change in momentum:
Change in momentum = - (mass density x area x length x velocity)
According to Newton's second law of motion, the force is equal to the rate of change of momentum. Therefore, the force that the water applies on the wall can be given by:
Force = change in momentum / time
Since the water hits the wall and stops instantaneously, we can consider the time interval to be very small or infinitesimal (∆t → 0). In this case, the force can be approximated as:
Force = (∆m x v) / ∆t
= (∆m x v) / 0
= infinity
Therefore, the force that the water applies on the wall is theoretically infinite since the water stops instantaneously. In practice, the force will be very large, causing the wall to experience a significant impact.
Note: This explanation assumes that there are no external factors such as friction or any other forces acting on the water jet.