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:
a
Explanation:
heat is energy, energy cannot be made or destroyed but transferred
Answer:
Galileo di Vincenzo Bonaiuti de' Galilei
<h2>
Hello!</h2>
The answer is:
The first option, the walker traveled 360m more than the actual distance between the start and the end points.
Why?
Since each block is 180 m long, we need to calculate the vertical and the horizontal distance, in order to calculate how farther did the travel walk between the start and the end points (displacement).
So, calculating we have:
Traveler:


Actual distance between the start and the end point (displacement):

Now, to calculate how much farter did the traveler walk, we need to use the following equation:

Therefore, we have that distance differnce between the distance covered by the walker and the actual distance is 360m.
Hence, we have that the walker traveled 360m more than the actual distance between the start point and the end point.
Have a nice day!
Answer:
1) The strength of the electromagnet increases → Place a magnetic core inside the coil of wire
2) The electromagnet turns off → Turn off the battery supply
3) The poles of the electromagnet reverse → Change the direction in which the current flows
Explanation:
when current passes through a coil it behaves a an electromagnet.
Magnetic field strength is given by
B = μ N I
N is no of turns and
I is the current through coil
μ is permeability of the medium or core in the coil.
1). Magnetic core increase permeability μ so it will strengthen magnetic field:
B = <u>μ</u> N I
2). When the battery turns off current becomes zeroi.e I=0
So B = μ N * 0
⇒ B = 0
so electromagnet turns off
3). Direction of magnetic field can be determine by right hand rule, i.e curl the fingers in the direction of current, thumb will point in the direction of north pole.
so changing current direction will change direction of magnetic field.