#21 A 0.30 kg softball has a velocity of 15 m/s at an angel of 35o below the horizontal just before making contact with the bat. What is the magnitude of the change in momentum of the ball while in contact with the bat if the ball leaves with a velocity of (a) 20 m/s, vertically downward, and (b) 20 m/s, horizontally back toward the pitcher?

Respuesta :

Answer:

a) 5 kg m/s

b) 10 kg m/s

Explanation:

GIVEN DATA:

mass of softball 0.30 kg

\theta = 35 degree

velocity = 15 m/s

Along the x axis we have

[tex]P_{xf} - P_{xi} = 0 - 0.3(15)cos 35 = - 3.68\hat i kg m/s[/tex]

along the y axis we have

[tex]P_{yf} - P_{yi} = -(0.3)20 - 0.3(15)sin 35 = - 3.41\hat j kg m/s[/tex]

The magnitude of momentum is

[tex]\Delta P = \sqrt{ (-3.41)^2 + (-3.68)^2} = 5 kg m/s[/tex]

b) Along the x axis we have

[tex]P_{xf} - P_{xi} = -0.3(20) - 0.3(15)cos 35 = - 9.68\hat i kg m/s[/tex]

along the y axis we have

[tex]P_{yf} - P_{yi} = -0 - 0.3(15)sin 35 = -25.58\hat j kg m/s[/tex]

The magnitude of momentum is

[tex]\Delta P = \sqrt{ (-9.68)^2 + (-2.58)^2} = 10 kg m/s[/tex]

The magnitude of the change in momentum of the ball will be 5kgm/s.

How to calculate the momentum?

The magnitude of the change in momentum of the ball while in contact with the bat if the ball leaves with a velocity of 20 m/s, vertically downward will be calculated thus:

x axis = -0.3(15) cos 35 = -3.68

y axis = -0.3(15) sin 35 = -3.41

Magnitude of momentum will be:

= ✓(-3.41)² + ✓(-3.68)²

= 5kgm/s.

The magnitude when the velocity is 20 m/s horizontally back toward the pitcher will be:

= ✓(-9.68)² + ✓(-2.58)²

= 10kg m/s.

Learn more about momentum on:

https://brainly.com/question/1042017