Sound level at distance of 15 m is given as 20 dB
so intensity at this distance is given as
now if we move closer to some some distance the sound level is now 50 dB
now the intensity is given as
now we know that
so now the distance from friend must be 47 cm
In Newton's third law, the action and reaction forces D.)act on different objects
Explanation:
Newton's third law of motion states that:
<em>"When an object A exerts a force on object B (action force), then action B exerts an equal and opposite force (reaction force) on object A"</em>
It is important to note from the statement above that the action force and the reaction force always act on different objects. Let's take an example: a man pushing a box. We have:
- Action force: the force applied by the man on the box, forward
- Reaction force: the force applied by the box on the man, backward
As we can see from this example, the action force is applied on the box, while the reaction force is applied on the man: this means that the two forces do not act on the same object. This implies that whenever we draw the free-body diagram of the forces acting on an object, the action and reaction forces never appear in the same diagram, since they act on different objects.
Learn more about Newton's third law of motion:
brainly.com/question/11411375
#LearnwithBrainly
In order to measure the size of the electrical current flowing in the circuit,
the current must pass through the meter.
Sunlight (white light) refracts through droplets of water in the atmosphere and this causes a rainbow in the sky. The correct option among all the options that are given in the question is the third option or option "C". The rainbow is caused by the reflection, refraction and dispersion of sunlight in water droplets that are present in the atmosphere.
Answer:
Energy = 1.38*10^13 J/mol
Explanation:
Total number of proton in F-19 = 9
Total number of neutron in F-19 = 10
Expected Mass of F-19
= 9*1.007 + 10*1.008 = 19.152 u
Actual mass of F-19 = 18.998 u
Energy of one particle of F-19 = 931.5*Δm = 931.5*(19.152-18.998)
= 143.234 MeV
Energy of one mole of F-19 = 143.234*10^6*1.6*10^-19*6.022*10^23
= 1.38*10^13 J/mol
