Answer:

Explanation:
we know that



as we see that 
relative error
Where X_1 IS HEIGHT OF ROCK
IS THE HEIGHT OF ROAD
= uncertainity in measuring distance

Putting all value to get uncertainity in angle

solving for
we get

Answer:
the group of units suggested by the international convention of scientists in 1960 AD to make similarties in meseurment all over the world is called SI units
A. hot is the correct answer.
Hope it helps!
Answer:
900 W.
Explanation:
Given that
Electric heater 1500 W
We know that power P given as
P= V I
So the total power of 120 V and 20 A circuit
P = 120 x 20
P= 2400 W
So the power new load P'
P'= Total system power(P)- Electric heater load
P ' = 2400 - 1500
P'= 900 W
So the answer is 900 W.