Answer:
A. The athlete isn’t doing any work because he doesn’t move the weight.
Explanation:
We must remember the definition of work, which says that work is equal to the product of mass by the distance displaced. In this case, the athlete only does work when he lifts the weight from the ground to the point where he holds the weight suspended.
So when he's holding the weight, he doesn't do any work.
Answer:
)Give the definition of poverty line as defined by the World Bank.
Q = mcθ
Where m = mass of water in kg.
c = specific heat capacity in kJ/kg⁰C, c for water = 4200 kJ/kg⁰C
θ = temperature rise in ⁰C
Q = 100*4200* 20 Note here the temperature rise is 20 ⁰C
Q = 8 400 000 J
In calories, 4.2 J = 1 Calorie
= 8 400 000 / 4.2 = 200 000
Q = 200 000 Calories
The answer should be B. a stable isotope to a decaying isotope.
