Question

what is difference between errors and uncertainty?​

Answer 1

Answer:

ERROR

It is the difference between actual and measured value.

UNCERTAINTY

It is basically the mean absolute error.

Explanation:

Suppose we have measured length of a rod as;

X1=4.1 , X2=4.2 , X3=4.3 , X4=4.4 , X5=4.0

We take mean of these values as:

Sum of values ÷ Total number of values

X1+X2+X3+X4+X5 ÷5

4.1+4.2+4.3+4.4+4.0 ÷ 5

21÷5

Ans 4.2

Hence 4.2 is the mean value

Now we take the absolute error in each value which is calculated as;

Mean - each X value

Absolute error in X1

4.2 - 4.1=0.1

Absolute error in X2

4.2 - 4.2=0

Absolute error in X3

4.2 -4.3 = -0.1

Absolute error in X4

4.2 - 4.4= -0.2

Absolute error in X5

4.2. - 4.0= 0.2

This is absolute error in each measured value.

NOTE:

Absolute error can be negative.

Now we take mean absolute error by adding all absolute errors in their modules (which converts negative values into positive ) and dividing them on 5 ( no. of values ).

So

0.1+0+0.1+0.2+0.2=0.6

Now 0.6 is the mean absolute error / uncertainty.

For representation of value , we first of all write the mean value ( which is the sum of errors and gives us an accurate value ) and then uncertainty in the value as,

4.2±0.6

Here 4.2 is the actual length of rod and ±0.6 is the uncertainty in it.

HOPE THIS HELPS YOU :)

HAVE A GOOD DAY!!!

Answer 2

what is the main difference between a pine tree and a scrub