Answer:
Tension, T = 87.63 N
Explanation:
Given that,
Mass of the object, m = 6.9 kg
The string is acting in the upward direction, a = 2.9 m/s²
Acceleration due to gravity, g = 9.8 m/s²
As the lift is accelerating upwards, it means the net force acting on it is given by :
T = m(a+g)
= 6.9 (2.9+9.8)
= 6.9(2.7)
= 87.63 N
So, the tension in the string is 87.63 N.
Data:
mass, m = 30.94 g
density, d = 19.32 g/cm^3
Formula: d = m / v => v = m / d = 30.94 g / 19.32 g/cm^3 = 1.60 cm^3
Then, the answer is the option C.
