Answer:
Part a)

Part b)

Part c)

Explanation:
Part a)
As we know that there is no external torque on the system of two twins
so here we will use



Part b)
Since angular momentum is conserved here as there is no external torque
so we will have



Part c)
Work done by both of them = change in kinetic energy
so we have




The acceleration of gravity on Moon B is D) 0.25 m/s2
Explanation:
The data listed in the problem are not clear: find them in the table attached.
The acceleration of gravity on a planet is given by the following equation:

where:
is the gravitational constant
M is the mass of the planet
R is the radius of the planet
Here we want to find the acceleration of gravity on the surface of Moon B, which has the following data:
(mass)
(radius)
And substituting into the equation, we find:

Learn more about gravity:
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Answer:
1.0 M HNO3 at 40<em>°C</em>
Explanation:
Rate of chemical reaction: This can be defined as the number of moles of reactant, converted or product formed per unit time.
Factors that affect rate of chemical reaction:
(a) Temperature: Generally, an increase in temperature increase the rate of chemical reaction by (1) increasing the number of particles with energy equal to or greater than the activation energy, (2) Increasing the average speed of all the reactant particles, due to greater kinetic energy, leading to higher frequency of collision.
(b) Concentration: An increase or decrease in the concentration of the reactant will result to a corresponding increase or decrease in the effective collision of the reactant and hence in the reaction rate.
other factors that affect the rate of chemical reaction are
(i) Nature of the reactant
(ii) Surface area of reactant
(iii) presence of light
(iv) presence of catalyst.
From the question above,
<em>The condition with the highest temperature and concentration will produce the GREATEST reaction rate.</em>
<em>And that is 1.0 M HNO3 at 40 °C</em>
Answer:
The minumum speed the pail must have at its highest point if no water is to spill from it
= 2.64 m/s
Explanation:
Working with the forces acting on the water in the pail at any point.
The weight of water is always directed downwards.
The normal force exerted on the water by the pail is always directed towards the centre of the circle of the circular motion.
And the centripetal force, which keeps the system in its circular motion, is the net force as a result of those two previously mentioned force.
At the highest point of the motion, the top of the vertical circle, the weight and the normal force on the water are both directed downwards.
Net force = W + (normal force)
But the speed of this motion can be lowered enough to a point where the normal force becomes zero at the moment the pail reaches the highest point of its motion. Any speed lower than this value would result in the water spilling out of the pail. The water would not be able to resist the force of gravity.
At this point of minimum velocity,
Normal force = 0
Net force = W
Net force = centripetal force = (mv²/r)
W = mg
(mv²/r) = mg
r = 0.710 m
g = 9.8 m/s²
v² = gr = 9.8 × 0.71 = 6.958
v = √(6.958) = 2.64 m/s
Hope this Helps!!!