For the work, applicate formula:

According our data:
W = 12000 N * 1,5 m
W = 18000 J
The work done is <u>18000 Joules.</u>
Answer:
T = 2490 newton
Explanation:
Given that,
Mass of a person, m = 50 Kg
Speed of the swing at the lowest point, v = 10 m/s
Length of the rope, r = 2.5 m
Tension formula is given by
T = mg + ma N
where, T - Tension in the string
m - mass of the body
g - acceleration due to gravity
a - acceleration of the body
Since the person is swinging, the acceleration of the body is given by
a = v²/r m/s²
= 10/2.5 m/s²
a = 40 m/s²
Substituting in T
T = 50 Kg x 9.8 m/s² + 50 Kg X 40 m/s²
= 490 + 2000 Kg m/s²
T = 2490 newton
Therefore the tension in the rope is 2490 newton
<span>The screw gauge doesn’t have a zero error when the zero of the main scale coincides with the zero of the vernier scale or circular scale.
In case they don’t coincide then the instrument screw gauge is said to have a zero error which can be positive zero error or a negative zero error. In order to get an exact measurement, the error is added or subtracted from the value measured.</span>