Answer:
negative at first.
Explanation:
It's important to disconnect the negative side at first, otherwise you can cause an electrical short if positive is removed first.
Answer:
4.24m/s
Explanation:
Potential energy at the top= kinetic energy at the button
But kinetic energy= sum of linear and rotational kinetic energy of the hoop
PE= mgh
KE= 1/2 mv^2
RE= 1/2 I ω^2
Where
m= mass of the hoop
v= linear velocity
g= acceleration due to gravity
h= height
I= moment of inertia
ω= angular velocity of the hoop.
But
I = m r^2 for hoop and ω = v/r
giving
m g h = 1/2 m v^2 + 1/2 (m r^2) (v^2/r^2) = 1/2 m v^2 + 1/2 m v^2 = m v^2
and m's cancel
g h = v^2
Hence
v= √gh
v= √10×1.8
v= 4.24m/s
Most of the radiation, however, is absorbed by the earth's surface. ... Every surface on earth absorbs and reflects energy at varying degrees, based on its color and texture. Dark-colored objects absorb more visible radiation; light-colored objects reflect more visible radiation.
