Answer:
The mass number 204 – 82 protons = 122 neutrons
Explanation:
Hope this helps!
Answer:
coal tar is one of the product of coal
The answer is energy.
Waves in the ocean are energy travelling along water.
Waves do not transport mass, they transport energy, this is the ability to perform work or exert force and distant points.
Although water seems to be travelling along with the wave, the molecules of water only move up and down; they do not travel along with the wave.
Answer:
the time needed for her to close the door is 1.36 s.
Explanation:
given information:
Force, F = 220 N
width, r = 1.40 m
weight, W = 790 N
height, h = 3.00 m
angle, θ = 90° = π/2
to find the times needed to close the door we can use the following equation
θ = ω₀t + 1/2 αt²
where
θ = angle
ω = angular velocity
α = angular acceleration
t = time
in this case, the angular velocity is zero. thus,
θ = 1/2 αt²
now, we can find the angular speed by using the torque formula
τ = I α
where
τ = torque
I = Inertia
we know that
τ = F r
and
I = 1/3 mr²
so,
τ = I α
F r = 1/3 mr² α
α = 3 F/mr
= 3 F/(w/g)r
= 3 (220)/(790/9.8) 1.4
= 5.85 rad/s²
θ = 1/2 αt²
π/2 = 1/2 5.85 t²
t = 1.36 s
