There are two types of forces
1. Physical force : in this type of forces we require direct contact between two bodies
2. Field force: here we do not requires any type of physical contact with the body
so here in this type of field force we do not required any contact but only due to field present near it the body can move
so here several examples are there
a) when a magnet is placed near a piece of iron then it will move towards the iron
b) a positively charged particle when come near another charged particle then it will get attracted or repelled.
so as per all above discussion we can say that an object can move without any direct contact
Answer:
If you count the number of seconds between the flash of lightning and the sound of thunder, and then divide by 5, you'll get the distance in miles to the lightning: 5 seconds = 1 mile, 15 seconds = 3 miles, 0 seconds = very close. Keep in mind that you should be in a safe place while counting.
Explanation:
The _quamtum mechanical_ model of the atom states that an electron's exact location within an atom can not be determined, but its probable location can be estimated within a three-dimensional region called an atomic orbital and that an electron's properties within an orbital can only be described by a set of mathematical values called a quantum number.
We can use Newton II here (where F=m*a), that F is the net (or resultant) force on the object, m is the mass of the object and a is the acceleration the object experiences.
This means, in this case there would be no friction and absolutely no other force which gives a component in the plane of motion, only then can you assume that F=804N.
Now using F= m*a
804 = 51.7*a
Therefore a = 804/51.7 = 15.55 m/s²