Question

A 110 kg football lineman is running to the right at 2.75 m/s while another 125 kg lineman is running to the left directly toward the first lineman at 2.6 m/s. a) What is the magnitude and direction of the net momentum of the two linemen? b) What is the total kinetic energy of the two linemen?

Answer 1

To solve this problem it is necessary to apply the equations concerning the moment and the total calculation of this.

The momentum can be defined as,

L = vm

Where,

m = mass

v = Velocity,

PART A) For this specific case we have two momentum that would be defined as

$L_T = L_1 -L_2$

$L_T = m_1v_1-m_2v_2$

$L_T = 110*2.75 - 125*2.60$

$L_T = - 22.5 Kgm/s$

PART B) Kinetic energy can be defined as

$KE = \frac{1}{2} mv^2$

Where,

m= mass

v= velocity

The total kinetic energy would be,

$KE = \frac{1}{2} m_1v_1^2+\frac{1}{2} m_2v_2^2$

$KE = 0.5*110*2.75^2 + 0.5*125*2.60^2$

$KE = 838.4375 J$