A person slaps her leg with her hand, which results in her hand coming to rest in a time interval of 2.65 ms from an initial speed of 5.25 m/s . What is the magnitude of the average contact force exerted on the leg, assuming the total mass of the hand and the forearm to be 1.75 kg

Respuesta :

Answer:

the magnitude of the average contact force exerted on the leg is  3466.98 N

Explanation:

Given the data in the question;

Initial velocity of hand vâ‚€ = 5.25 m/s

final velocity of hand v = 0 m/s

time interval t = 2.65 ms = 0.00265 s

mass of hand m = 1.75 kg

We calculate force on the hand F[tex]_{hand[/tex]

using equation for impulse in momentum

F[tex]_{hand[/tex] × t = m( v - v₀ )

we substitute

F[tex]_{hand[/tex] × 0.00265  = 1.75( 0 - 5.25 )

F[tex]_{hand[/tex] × 0.00265  = 1.75( - 5.25 )

F[tex]_{hand[/tex] × 0.00265  = -9.1875

F[tex]_{hand[/tex] = -9.1875 / 0.00265  

F[tex]_{hand[/tex] = -3466.98 N

Next we determine force on the leg F[tex]_{leg[/tex]

Using Newton's third law of motion

for every action, there is an equal opposite reaction;

so, F[tex]_{leg[/tex] = - F[tex]_{hand[/tex]

we substitute

F[tex]_{leg[/tex] = - ( -3466.98 N )

F[tex]_{leg[/tex] = 3466.98 N

Therefore, the magnitude of the average contact force exerted on the leg is  3466.98 N