Answer:
296.01 J
Explanation:
From the question,
Q = cm(t₂-t₁)....................... Equation 1
Where Q = quantity of heat, c = specific heat capacity of aluminium, m = mass of aluminium, t₁ = Initial temperature, t₂ = Final temperature
Given: c = 897 J/kg.K, m = 0.01 kg, t₁ = 22 K, t₂ = 55 k
Substitute these values into equation 1
Q = 897×0.01×(55-22)
Q = 897×0.01×33
Q = 296.01 J
Hence 296.01 Joules of heat is required.
The most reactive element of this list is Chlorine, the next most reactive is bromine, and the least reactive is iodine.
All of these three elements are group 7 elements in the periodic table. It is known that the reactivity of group 7 elements decreases down the group. The most reactive element in this group is Flourine with reactivity decreasing down the group.
The reason for this decrease in reactivity is that as you go down the group, the distance between the positive nucleus that attracts valence electrons increases, decreasing the electrostatic attraction between the nucleus and the outer electrons. The other reason is that the electrons in lower energy levels closer to the nucleus repel and shield the electrons in the outermost shell or energy level of the atom.
Chlorine>Bromine>Iodine.
Answer:
the intensity of the sound waves produced by one 60-w speaker at a distance of 1.0 m is 60 w/m²
Explanation:
Intensity of sound , I, is given as;
I = P/A
Where;
P is the power through an area = 60-w
A is the area = ?
A = 1.0m × 1.0m = 1.0 m²
I = 60-w / 1.0 m²
I = 60 w/m²
Therefore, the intensity of the sound waves produced by one 60-w speaker at a distance of 1.0 m is 60 w/m²
Answer is B! Hope you have a good day
Average acceleration is how much the car increases (on average) per second. So, since it increases by 30 m/s in 8 s, then dividing 30 by 8 will give you an average acceleration of 3.75 m/s^2 (remember that acceleration is ever increasing, so the unit is s^2, not just s)
Hope this helps!