We are to show that the given parametric curve is a circle.
The trajectory of a circle with a radius r will satisfy the following relationship:

(with (x_c,y_c) being the center point)
We are given the x and y in a parametric form which can be further rewritten (using properties of sin/cos):

Squaring and adding both gives:

The last expression shows that the given parametric curve is a circle with the center (0,0) and radius A.
If you travel 30 miles somewhere and then come home again your distance is 60 miles. Your displacement is 0 because it is the ending position minus the beginning position, which are the same place (home). In other words, displacement is a vector and distance is a scalar.
The kinetic energy of the child at the bottom of the incline is 106.62 J.
The given parameters:
- <em>Mass of the child, m = 16 kg</em>
- <em>Length of the incline, L = 2 m</em>
- <em>Angle of inclination, θ = 20⁰</em>
The vertical height of fall of the child from the top of the incline is calculated as;

The gravitational potential energy of the child at the top of the incline is calculated as;

Thus, based on the principle of conservation of mechanical energy, the kinetic energy of the child at the bottom of the incline is 106.62 J since no energy is lost to friction.
Learn more about conservation of mechanical energy here: brainly.com/question/332163
Answer: (d)
Explanation:
Given
Mass of object 
Speed of object 
Mass of object at rest 
Suppose after collision, speed is v
conserving momentum

Initial kinetic energy

Final kinetic energy

So, it is clear there is decrease in kinetic energy . Thus, energy decreases and velocity becomes 2 m/s.
A Parallel circuit has certain characteristics and basic rules: A parallel circuit has two or more paths for current to flow through. Voltage is the same across each component of the parallel circuit. The sum of the currents through each path is equal to the total current that flows from the source.