Answer:
Explanation:
The hand provides Kinetic Energy in moving.
The KE is transformed to Frictional energy
The Frictional Energy can produce heat and light energy.
The sandpaper produces little shreds from the grit of the paper.
The shreds have KE (they move)
Answer:
f = 19,877 cm and P = 5D
Explanation:
This is a lens focal length exercise, which must be solved with the optical constructor equation
1 / f = 1 / p + 1 / q
where f is the focal length, p is the distance to the object and q is the distance to the image.
In this case the object is placed p = 25 cm from the eye, to be able to see it clearly the image must be at q = 97 cm from the eye
let's calculate
1 / f = 1/97 + 1/25
1 / f = 0.05
f = 19,877 cm
the power of a lens is defined by the inverse of the focal length in meters
P = 1 / f
P = 1 / 19,877 10-2
P = 5D
Answer:
The articles appearing under "Milestones in Physics" will give an insight into special events or situations that have been decisive for the evolution of Physics
Average speed=total distance traveled/time. Total distance=the sum of the two short distances=79*2+77*3=389 km. Total time used to travel is 2+3=5 hr. Average speed is 389/5=77.8 km/hr.
Answer: D
Explanation: there is less light at that point.
