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:
The time is 5.10 sec.
Explanation:
Given that,
Component of velocity are 30 m/s and 40 m/s.
We need to calculate the resultant velocity
Using formula of resultant velocity

Put the value into the formula

[
We need to calculate the time
Using equation of motion



Put the value into the formula


Hence, The time is 5.10 sec.
Answer:
The best estimate of the depth of the well is 2.3 sec.
Explanation:
Given that,
Record time,





We need to find the best estimate of the depth of the well
According to record time,
We can write of the record time





Here, all time is nearest 2.3 sec.
So, we can say that the best estimate of the depth of the well is 2.3 sec.
Hence, The best estimate of the depth of the well is 2.3 sec.
Answer:
Lenz's law, in electromagnetism, statement that an induced electric current flows in a direction such that the current opposes the change that induced it. This law was deduced in 1834 by the Russian physicist Heinrich Friedrich Emil Lenz (1804–65).
R is proportional to the length of the wire:
R ∝ length
R is also proportional to the inverse square of the diameter:
R ∝ 1/diameter²
The resistance of a wire 2700ft long with a diameter of 0.26in is 9850Ω. Now let's change the shape of the wire, adding and subtracting material as we go along, such that the wire is now 2800ft and has a diameter of 0.1in.
Calculate the scale factor due to the changed length:
k₁ = 2800/2700 = 1.037
Scale factor due to changed diameter:
k₂ = 1/(0.1/0.26)² = 6.76
Multiply the original resistance by these factors to get the new resistance:
R = R₀k₁k₂
R₀ = 9850Ω, k₁ = 1.037, k₂ = 6.76
R = 9850(1.037)(6.76)
R = 69049.682Ω
Round to the nearest hundredth:
R = 69049.68Ω