A1300 kg weather rocket accelerates upward at 10m/s2. it explodes 1.5 s after liftoff and breaks into two fragments, one twice as massive as the other. photos reveal that the lighter fragment traveled straight up and reached a maximum height of 500 m . part a what was the speed of the heavier fragment just after the explosion?

To solve this problem it is necessary to apply the conservation equations of the Momentum. The equation that represents such momentum conservation is given by,

Final momentum = Initial momentum

Where,

=mass light

= mass heavy

= velocity of mass light

= velocity of mass heavy

= final velocity

One of the masses is heavier than the other previously detached so we will assume that mass is 1/3 of the total, and the heavy mass is 2/3 of the total.

We start finding the initial velocity, then

The distance traveled is then calculated by the kinematic equations of motion,

The speed of the lighter piece is given also for the kinematic equation of movement,

Replacing at the conservation of momentum equation we have,

Therefore the speed of the heavier fragment just after the explosion is 18.52m/s against the direction of movement.

air exerts forces on falling objects near earth’s surface.

explanation:

the term 'free falls' refer to object that are falling towards the earth, in a situation in which gravity is the only force acting on the object.

for an object in free fall, the acceleration is constant (g, the gravitational acceleration), and so the velocity of the object constantly increases.

for objects near earth's surface, there is always another force acting on the object: the resistance due to the air. this force is opposed to the direction of fall of the object, and it is proportional to the velocity of the object, so as the object falls down, this force increases up to a point when it balances the force of gravity, and the object continues its motion at constant velocity (called terminal velocity). since in this case gravity is not the only force acting on the object, we are not in a situation of free fall.