Assuming it is on a horizontal surface:
friction = μR
R = 20g (g is gravity 9.81)
so Friction = 0.085 x 20g
Work done is force x distance
so Work done = 0.085 x 20g x 28
= 466.956 J
I’m pretty sure it’s c.... hope it helps and hope it’s right.
Answer:
The gravitational force between m₁ and m₂, is approximately 1.06789 × 10⁻⁶ N
Explanation:
The details of the given masses having gravitational attractive force between them are;
m₁ = 20 kg, r₁ = 10 cm = 0.1 m, m₂ = 50 kg, and r₂ = 15 cm = 0.15 m
The gravitational force between m₁ and m₂ is given by Newton's Law of gravitation as follows;

Where;
F = The gravitational force between m₁ and m₂
G = The universal gravitational constant = 6.67430 × 10⁻¹¹ N·m²/kg²
r₂ = 0.1 m + 0.15 m = 0.25 m
Therefore, we have;

The gravitational force between m₁ and m₂, F ≈ 1.06789 × 10⁻⁶ N
Given Information:
Current = I = 2.5 A
Magnetic field = B = 0.10 T
Radius = r = d/2 = 0.02/2 = 0.01 m
Length = L = 8 cm = 0.08 m
Required Information:
Number of turns = N = ?
Answer:
Number of turns = N ≈ 2547 turns
Step-by-step explanation:
The approximate model to find the number of turns is given by
B = μ₀nI
Where n = N/L
so
B = μ₀NI/L
N = BL/μ₀I
Where B is the magnetic field, L is the length of the solenoid, I is the current and μ₀ is the permeability of free space
N = (0.10*0.08)/(4πx10⁻⁷*2.5)
N ≈ 2547 Turns
That matter s indivisible and indestructible. This is because they discovered that certain elements, thought to be indivisible, can breakdown by radioactive decay and emit smaller, high energy particles and/or photons.