Thumbtacks have a flat top which gives you a bigger area to push on, and the end is tapered and sharp to make it easier to push it into a wall, etc.
Answer:
angular speed = 0.4 rad/s
Explanation:
given data
radius = 5 m
moment of inertia = 2000 kg-m²
angular speed = 1.0 rad/s
mass = 60 kg
to find out
angular speed
solution
Rotational momentum of merry-go-round = I?
we get here momentum that is express as
momentum = 2000 × 1
momentum = 2000 kg-m²/s
and
Inertia of people will be here as
Inertia of people = mr² = 60 × 5²
Inertia of people = 1500 kg-m²
so Inertia of people for two people
1500 × 2 = 3000
and
now conserving angular momentum(ω)
moment of inertia × angular speed = ( momentum + Inertia of people ) angular momentum
2000 × 1 = (2000 + 3000 ) ω
solve we get now
ω = 0.4 rad/s
Answer:
A. Endothermic reaction.
B. +150KJ.
C. 250KJ.
Explanation:
A. The graph represents endothermic reaction because the heat of the product is higher than the heat of the reactant.
B. Determination of the enthalpy change, ΔH for the reaction. This can be obtained as follow:
Heat of reactant (Hr) = 50KJ
Heat of product (Hp) = 200KJ
Enthalphy change (ΔH) =..?
Enthalphy change = Heat of product – Heat of reactant.
ΔH = Hp – Hr
ΔH = 200 – 50
ΔH = +150KJ
Therefore, the enthalphy change for the reaction is +150KJ
C. The activation energy for the reaction is the energy at the peak of the diagram.
From the diagram, the activation energy is 250KJ.
B- lack of control.
the scientists did not have a proper control group.
Answer:
i. 0.34
ii. 0.4
iii. 1700 w/m²
iv. 2211.36 w/m²
Explanation:
Given that
Irradiation of the plate, G = 2500 w/m²
Reflected rays, p = 500 w/m²
Emissive power, E = 1200 w/m²
See attachment for calculations
