That's the description of a ground fault circuit interrupter (GFCI).
The choices you posted seem to belong to a different question.
The sleds speed when the spring returns toits uncompressed length is v = 0.03 m/s.
<u>Explanation</u>:
Given,
force constant = 42 N/cm = 0.42 N/m, mass m = 68 kg, spring x = 0.39 m
The potential energy, U, stored in the spring is
U = 1/2 kx^2
= 1 / 2
0.42
(0.39)^2
= 0.032 J
All its potential energy has been converted into kinetic energy since it has a uncompressed length.
K = 1/2 mv^2
v = sqrt (2K / m)
= √(( 2
0.032) / 68)
v = 0.03 m/s
.
D - tertiary consumer
This is because it is the farther up to food chain.
F = normal force by each board on each side
W = weight of the board in between acting in down direction = 95.5 N
f = frictional force in upward direction by each board
= coefficient of friction = 0.663
Using equilibrium of force in Upward direction
f + f = W
f = W/2
f = 95.5/2 = 47.75 N
frictional force is given as
f =
F
47.75 = (0.663) F
F = 72.02 N
Answer:
The H-R diagram can be used by scientists to roughly measure how far away a star cluster or galaxy is from Earth. This can be done by comparing the apparent magnitudes of the stars in the cluster to the absolute magnitudes of stars with known distances (or of model stars).