To solve this problem it is necessary to apply the concepts related to the Conservation of Energy, for which it is necessary that any decrease made through the potential energy, is equivalent to the gain given in the kinetic energy or vice versa.
Mathematically this can be expressed as
Since there is no final potential energy (the height is zero), and the initial potential energy is equivalent to the work done we have to
Therefore the non-conservative work was done on the boy is 1.4kJ
Answer:
<em>Time period of pendulum is 2.02 s.</em>
Explanation:
A <em>simple pendulum</em> is a device which consists of mass m hanging from the string of length L attached to the some point.When displaced and released its swings back and forth with periodic motion.
The time period of pendulum is defined as time taken by the pendulum to complete one full oscillation . it is denoted by T.
By <em>Huygens law of period of pendulum</em>,
T = 2π eqn 1
where L is the length of pendulum,
g is acceleration due to gravity
<em>Period of pendulum is independent of the mass of pendulum,</em>
<em />
Substituting values in eqn 1
T = 2π
T = 2.02 s
<em>Time period of pendulum is 2.02 s.</em>
Answer:
57 kg
Explanation:
Mass of seesaw = 20 kg
Length of seesaw = 4 m
Mass of child on the longer end = 30 kg
The weight of the seesaw acts at the center i.e. 2m
The algebraic sum of moments of all forces about any point is zero, hence, using the fulcrum as the reference point:
[x * 9.8* 1.5] - [20 * 9.8* (2.5 - 2)] - [30 * 9.8 * 2.5] = 0
=> 14.7x = (20*9.8*0.5) + 735
14.7x = 98 + 735
14.7x = 833
=> x = 833/14.7
x = 57 kg
