Answer:
Efficiency = 80%
Explanation:
Given the following data;
Work output = 240 N
Work Input = 300 N
To find the mechanical efficiency of a machine;
Substituting into the equation, we have;

Efficiency = 80%
Therefore, the mechanical efficiency of the machine is 80 percent.
Answer:
0 J
Explanation:
given,
mass of the ball = 5 kg
radius of the horizontal circle = 0.5 m
tension in the string = 10 N
Work done = ?
Work done by the tension in the circular path will be equal to zero.
This is because body moves in circular path, the centripetal force act along the radius of the circle and motion is right angle to the tension on the string.
so, work done = F s cos θ
θ = 90°,
work done = F s cos 90° ∵ cos 90° = 0
Work done = 0 J
Answer:

Explanation:
A 6.0-cm-diameter parallel-plate capacitor has a 0.46 mm gap.
What is the displacement current in the capacitor if the potential difference across the capacitor is increasing at 500,000V/s?
Let given is,
The diameter of a parallel plate capacitor is 6 cm or 0.06 m
Separation between plates, d = 0.046 mm
The potential difference across the capacitor is increasing at 500,000 V/s
We need to find the displacement current in the capacitor. Capacitance for parallel plate capacitor is given by :
, r is radius
Let I is the displacement current. It is given by :

Here,
is rate of increasing potential difference
So

So, the value of displacement current is
.
Answer:
An atom is the smallest constituent unit of ordinary matter that constitutes a chemical element. Every solid, liquid, gas, and plasma is composed of neutral or ionized atoms. Atoms are extremely small; typical sizes are around 100 picometers.Explanation:
Answer:
Wilhelm Conrad Roentgen (1845-1923)
Antoine Henri Becquerel (1852-1908)
Pierre (1859-1906) and Marie (1867-1934) Curie
Explanation:
Wilhelm Conrad Roentgen (1845-1923)
Contribution: Discovery of x-rays in 1901.
Antoine Henri Becquerel (1852-1908)
Contribution: He discovered that radioactivity is the separation of x-rays and document and the difference between two.
Pierre (1859-1906) and Marie (1867-1934) Curie
Contribution: She discovered Polonium and Radium in1911