The first one is D hunted with stone-tipped spears
The second one is A
Hope this helps
Answer:
similar type of electric charges attract one another
I think this is a coorect staement
Answer:
Correct option is
B
3
20
cm
Given; Focal length, f=20cm
Object distance, u=−10cm
Using mirror formula.
v
1
+
u
1
=
f
1
v
1
=
f
1
−
u
1
=
20
1
−
−10
1
(∵u=−10)
=
20
1
+
10
1
=
20
3
⇒v=
3
20
cm
Answer:
k_max = 31.82 w/mk
k_min = 17.70 w/mk
Explanation:
a) the maximum thermal conductivity is given as
where k_m is thermal conductvitiy of metal
k_p is thermal conductvitiy of carbide
v_m = proportion of metal in the cement = 0.17
v_p = proportion of carbide in the cement = 0.83
= 66*0.17 + 28*0.83
k_max = 31.82 w/mk
b) the minimum thermal conductivity is given as
= \frac{28+66}{28*0.17 +66*0.83}
k_min = 17.70 w/mk
Answer:
1/ As a metal has higher melting point than a nonmetal has, we can guess that sample A is a metal.
2/ The melting point is over 1000 gradius Celcius: 1083 - it's not a low value. And as the sample conducts heat, it is not the element of period N3 in the periodic table, because elements in period 3 do not conduct electricity.
Explanation:
I can not see what the questions 2-3 in your picture is. I answered the question above the table: What can the student conclude about thenidentity of Sample A.
