Answer:
1) Joule
2) kgm²/s²
3) 10%
Explanation:
Question 1)
Luminosity is defined as the total amount of energy released from an object in a unit amount of time.
This means Luminosity is the ratio of energy and time.
Unit of Energy is Joules and Unit of Time is seconds, so unit of Luminosity would be Joule per second or Watts.
So, from the given options, the unit which would be used in Luminosity calculations is Joule.
Question 2)
Work = Force x Distance
SI unit of Work is Joule
SI unit of Force is Newton or kgm/s²
SI unit of Distance is meter(m)
Unit of Work = Unit of Force x Unit of Distance
Joule = kgm/s² x m
Joule = kgm²/s²
This means, the correct description of joule in terms of SI base units is kgm²/s²
Question 3)
Value of gravitational constant from the experiment = Nm²/kg²
The accepted or actual value of the gravitational constant = Nm²/kg²
We need to calculate the percentage error. Percentage error is defined as:
Here, original value is the accepted value. Using the values in this formula, we get:
Thus, this means the percentage error in the calculation of gravitational constant was 10%.
Answer: Bohr's model
Explanation:
The Bohr's model is also known as the solar system model which describe that an atoms are basically imagine in the form of solar system. The Bohr's model basically describe about the atoms that it consist of nucleus with the number of electron in an orbit by using the electrostatic attraction.
The Bohr's model are introduced for overcoming the drawback in the Rutherford model as he proposed an idea that at different energy levels the electron can revolve in certain orbits around nucleus.
Answer:
The magnitude of the drills angular acceleration is .
The drill makes 50 revolutions before it stops.
Explanation:
The revolutions that the drill makes in 1 second is
And the angular velocity is
(<em>one revolution is </em><em> radians)</em>
Now, the drill comes to a halt in 2.5 s, which means the magnitude of it's angular acceleration is
In other words, the magnitude of the angular acceleration is
Now, we find the angular displacement of the drill which is given by the equation
putting in , , and , we get:
which is
<em>(one revolution is </em><em> radians)</em>
50 revolutions.
In other words ,the drill makes 50 revolutions before it stops.
Answer:
Option (a)
Explanation:
Given that,
Mass of a car, m = 1200 kg
Force exerted by the engine, F = 600 N
Noe force,F = ma
a is the acceleration of the engine
So, the acceleration of the car is 0.5 m/s².