A bird perched on a swing like the one below has a mass of 50.9 g, and the base of the swing has a mass of 145 g. The acceleration of gravity is 9.81 m/s^2. The swing and bird are originally at rest. Without flapping its wings, the bird jumps off the perch horizontally at 3.25 m/s to reach its food bowl. How high will the base of the swing rise above its original level? Disregard friction. Answer in units of m.

i think they are all correct

explanation:

they seem good

kepler used the data from tycho blahe (his mentor) to construct the laws of planetary motion.

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.