Hi there!
Recall the conservation of momentum:
For this type of inelastic collision:
Thus, the initial momentum equal the final momentum if there are no external forces.
We can begin by writing out this problem:
Answer:
Tension force does no work
78 m/s
55701 J
Explanation:
The work done by the tension force of the rope is the dot product of the tension force vector and the distance travel vector as he swings. However, as these 2 vectors are always perpendicular to each other, their dot product would be 0 (cos(90) = 0). So the work done by tension force is 0.
If we neglect air resistance, then only gravity does work on the swimmer. We can apply the following energy conservation equation to calculate the kinetic energy once we let go of the rope.
where m is the mass of the swimmer, g = 9.81 m/s2 is the gravitational constant, Δh = 415 - 105 = 310 m is the height difference as he swings from horizontal point to the let go point. v is the let go speed. We can divide both sides by m
If the swimmer actually end up with only 67.8 m/s, then the loss in kinetic energy is due to air resistance during the swinging process. We can also find this by calculating the difference between the kinetics energies
Answer:
The nephew
Explanation:
The dog's foot prints are overlapping the shoes that are overlapping the tire marks from 3 different tires, if the dog is his seeing dog then it would make sense that the dog's foot prints are next to his and they're going in the same direction, and since the dog's footprints overlap the others it means that they were there last.
People were confused so I'll resay it. The dog is the nephew's seeing dog, so he walks beside him. And if the dog's foot prints are overlapping all of the other's, that means the dog was there after all of the rest of them, and if the nephew is with the dog then the nephew was there last.
Answer:
Absorption Spectrum
Explanation:
The hot, dense source emits high energy photons of all wavelengths. Some of these photons are absorbed by electrons of cloud to excite them to a higher energy level which appear as dark lines in the spectra and we get Absorption Spectrum.