An 80-kg quarterback jumps straight up in the air right before throwing a 0.43-kg football horizontally at 15 m/s . how fast will he be moving backward just after releasing the ball? sort the following quantities as known or unknown. take the horizontal direction to be along the x axis. mq: the mass of the quarterbackmb: the mass of the football(vqx)i: the horizontal velocity of quarterback before throwing the ball(vbx)i: the horizontal velocity of football before being thrown(vqx)f: the horizontal velocity of quarterback after throwing the ball(vbx)f: the horizontal velocity of football after being thrownobvioulsy the two massses are known and i assumed the speed of the football after being thrown and possibly before too? so what else am i missing?

grav force prop 1/r squared 2r all squared is 4rsquared 1/4rsquared quartered

force is based upon mass and acceleration.the statement is not always true.

it can be explained from newton's second law of motion.

as per newton's second law of motion the rate of change of momentum is directly proportional to the applied force and takes place along the direction of force.

mathematically it can be written as -

                                              ⇒      

here   k is the proportionality constant whose value is 1.

                                                            [a is the acceleration=dv/dt]

hence we see that force not only depends on mass and acceleration but also on velocity and rate of change of mass. force f will depend on mass and acceleration only when mass is constant.

hence the statement that force is based upon mass and acceleration is false.