On question 30, that is a displacement- time graph (DT). On this type of graph the gradient is equal to the velocity. B has the steepest gradient, then A and finally C
Now velocity is a vector quantity so it has a direction and speed ( speed doesn't have a fixed direction.)
on the DT graph im going to assume that movement B is a positive velocity with A and C being negative.
So by ranking these: A is the most negative, C is the least negative and B has to be the greatest as it is the only positive velocity.
Q31, The same type of graph is present, by looking at the gradients we can rank the largest and smallest velocities- speeds in the case of the question.
i'll skip my working out as its the same as before:
C, B, A and then D
the same idea as on Q30 applies to Q31 part b,
D,C,B then A
Answer:
c - until it becomes a different, stable element
Explanation:
found it somewhere else than brainly you're welcome :)
Answer:
The minimum value is 
Explanation:
From the question we are given that
The voltage is 
The internal resistance is 
The objective of this solution is to obtain the minimum value of the voltmeter resistance for which the voltmeter reading is within 1.0% of the emf of the battery
What is means is that we need to obtain voltmeter resistance such that
V = (100% -1%) of E
Where E is the e.m.f of the battery and V is the voltmeter reading
i.e V = 99% of E = 0.99 E = 7.425
Generally
E = V + ir
where ir is the internal potential difference of the voltmeter and
V is the voltmeter reading
Making i the subject of the formula above



Now the current is constant through out the circuit so,

Where
is the value of voltmeter resistance
Hence 

D, which is around the speed of light