Three forces involved in brushing your teeth are first push, then pull, then push.
Answer:
w₂ = 22.6 rad/s
Explanation:
This exercise the system is formed by platform, man and bricks; For this system, when the bricks are released, the forces are internal, so the kinetic moment is conserved.
Let's write the moment two moments
initial instant. Before releasing bricks
L₀ = I₁ w₁
final moment. After releasing the bricks
= I₂W₂
L₀ = L_{f}
I₁ w₁ = I₂ w₂
w₂ = I₁ / I₂ w₁
let's reduce the data to the SI system
w₁ = 1.2 rev / s (2π rad / 1rev) = 7.54 rad / s
let's calculate
w₂ = 6.0/2.0 7.54
w₂ = 22.6 rad/s
Answer:
A. carbon and boron
Explanation:
Carbon and boron is not an alloy.
An allow forms between metals and metals using their huge electron could.
Carbon is a non-metal, boron is a also a non-metal
Two non-metals combining together does not make an alloy.
Iron, nickel, aluminum are all metals.
Potential energy at top:
PE = mgh
PE = 40 x 9.81 x 12
P.E = 4,708.8 J
Kinetic energy at bottom:
KE = 1/2 mv²
KE = 1/2 x 40 x 10²
K.E = 2,000 J
P.E = K.E + Frictional losses
Frictional losses = 4708 - 2000
Frictional losses = 2708 J
The answer is D.