Since heat here is conserved that means that the heat out is equal to the heat in. We use the expression Q = mC(T2-T1). We caclulate as follows:
Q absorbed = Q released
m1 C (T-T1) = -m2 C (T-T1)
C can be cancelled since they are the same substance.
m1 (T-T1) = -m2 (T-T1)
25 (T-10) = -12 (T-30)
T = 16.49 degrees Celsius
The gravitational potential energy of the brick is 25.6 J
Explanation:
The gravitational potential energy of an object is the energy possessed by the object due to its position in a gravitational field.
Near the surface of a planet, the gravitational potential energy is given by

where
m is the mass of the object
g is the strength of the gravitational field
h is the height of the object relative to the ground
For the brick in this problem, we have:
m = 8 kg is its mass
g = 1.6 N/kg is the strenght of the gravitational field on the moon
h = 2 m is the height above the ground
Substituting, we find:

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Answer:
24.348mm
Explanation:
NB: I'll be attaching pictures so as to depict missing mathematical expressions or special characters which are not easily found on keyboards
K = d / €^n
Note : d represents the greek alphabet epsilion.
K = 345 / 0.02⁰.²² = 816mPa
The true strain based upon the stress of 414mPa =
€= (€/k)^1/n = (414/816)¹/⁰.²² = 0.04576
However the true relationship between true strain and length is given by
€ = ln(Li/Lo)
Making Li the subject of formula by rearranging,
Li = Lo.e^€
Li = 520e⁰.⁰⁴⁵⁷⁶
Li = 544.348mm
The amount of elongation can be calculated from
Change in L = Li - Lo = 544.348 - 520 change in L = 24.348mm.
Answer:
1. The force of the shelf holding the book up.
Explanation:
The free body diagram of the book is as follows:
1 - The weight of the book towards downwards
2 - The normal force that the shelf exerts on the book towards upwards.
Since the book is at rest, these two forces are equal to each other and according to Newton's Third Law the reaction force to the force of gravity is equal but opposite to the weight of the book. This reaction force is the one that holds the book up on the shelf.
First of all, we can find the mass of the person, since we know his weight W:

And so

We know for Newton's second law that the resultant of the forces acting on the person must be equal to the product between the mass and the acceleration a of the person itself:

There are only two forces acting on the person: his weight W (downward) and the vincular reaction Rv of the floor against the body (upward). So we can rewrite the previous equation as

We know the acceleration of the system,

(upward, so with same sign of Rv), so we can solve to find the value of Rv, the normal force exerted by the elevator's floor on the person: