An 83.5 kg fullback moving east with a speed of 5.0 m/s is tackled by a 84.5 kg opponent running west at 2.66 m/s, and the collision is perfectly inelastic. (a) Calculate the velocity of the players just after the tackle. m/s (b) Calculate the decrease in kinetic energy during the collision. J

(a) 1.15 m/s

(b) 1231.60 J

Explanation:

Given:

Mass of fullback (m) = 83.5 kg

Mass of opponent (M) = 84.5 kg

Initial velocity of fullback (u) = 5.0 m/s

Initial velocity of opponent (U) = -2.66 m/s

The collision is perfectly inelastic. So, both the fullback and opponent stick together after collision and travel with same velocity.

(a)

Let the final velocity be 'v'.

The total momentum before and after collision is conserved. Therefore,

Initial momentum = Final momentum

Initial momentum of fullback + opponent = Final momentum of fullback + opponent

Plug in the given values and solve for 'v'. This gives,

Therefore, the velocity of the players just after the tackle is 1.15 m/s.

(b)

The decrease in kinetic energy is given as:

Initial kinetic of the players is given as:

Final kinetic energy of the players is given as:

Therefore, the decrease in kinetic energy is given as:

Decrease =

the box does not move because you need to use a force greater than 300 n. you are only using 50 n. it needs to at least be 301 n for the box to move because then it is an unbalanced force and it will move the way that the greater force is pushing it. if you use only 300 n it will be a balanced force and will not move because the force you are exerting on the   box is the same as its force.

hope this !

im sorry if i went too in depth, i am going to include a link to a video on khan academy that will explain this.   hope that you like the video and that it explains more in detail to you.

that is the link.