A 68.5kg astronaut floating motionless next to the space station throws a 2.25kg tool away from her at 3.20m/s. With what speed and direction will the astronaut begin to move?

-0.105 m/s

Explanation:

Given that

Mass of the astronaut, m(a) = 68.5 kg

Mass of the tool, m(t) = 2.25 kg

Speed of the tool after it is thrown, v(t) = 3.20 m/s

We know that momentum of a particle,

p = mv

See the attachment for calculations

Therefore, the speed is 0.105 m/s and it moves in the opposite direction.

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.