The correct answer is (A) 2.0 J
Total energy of the pendulum is the sum of its kinetic and potential energy. At the instant of time, when the pendulum is at a height <em>h</em> and has a speed <em>v, </em>Its energy is given by,
Substitute 2.0 kg for <em>m</em>, the mass of the pendulum, 9.81 m/s² for <em>g</em>, the acceleration due to gravity, 0.10 m for <em>h and 4.0 m/s for </em>v<em>.</em>
The pendulum has an initial energy of 20 J. the energy lost is given by,
Thus, the energy lost by the pendulum is (A) 2.0 J
Answer:
Scientific models have two basic types. FALSE.
Hoped I helped
<h2>
Person must have 8.18 m/s to catch the ball</h2>
Explanation:
Consider the vertical motion of ball
We have equation of motion s = ut + 0.5at²
Initial velocity, u = 12 m/s
Acceleration, a = -9.81 m/s²
Displacement, s = -25 m
Substituting
-25 = 12 x t + 0.5 x -9.81 x t²
4.905 t² -12t - 25 = 0
t = 3.79 sec
Ball hits ground after 3.79 seconds.
So person need to cover 31 m in 3.79 seconds
Consider the horizontal motion of person
We have equation of motion s = ut + 0.5at²
Initial velocity, u = ?
Acceleration, a = 0 m/s²
Displacement, s = 31 m
Time, t = 3.79 seconds
Substituting
31 = u x 3.79 + 0.5 x 0 x 3.71²
u = 8.18 m/s
Person must have 8.18 m/s to catch the ball
To determine the displacement, since we are given the potential energy, we use the equation for potential energy. For a spring, it is one-half the product of the spring constant and the square of the displacement. We do as follows:
PE = kx^2/2
5 Nm = 50N/m (x^2)
x = 0.32 m
Therefore, the displacement would be 0.32 m.
