Answer:
Friction between the box and the floor is 25N to the left
Explanation:
There are two forces acting on the box along the horizontal direction:
- The force of push applied by the worker, in the forward direction, F
- The force of friction,
, acting in the opposite direction (backward)
So the net force acting on the box is

According to Newton's second law of motion, the net force on an object is equal to the product between its mass (m) and its acceleration (a), so we can write:

And so

However, in this case the box is moving at constant speed; this means that its acceleration is zero:

Therefore we have:

Which means

And since we are told that

This means that the force of friction is also 25 N:

Answer:
dependent variables
Explanation:
dependent varibeles are the thing you're measuring and independent variables are the thing you change in the exeriment to get a different dependent variable.
may I get brainliest please? :)
Answer:
Explanation:
Number of turns
N = 210turns
Length of solenoid
l = 0.18m
Cross sectional area
A = 4cm² = 4 × 10^-4m²
A. Inductance L?
Inductance can be determined using
L = N²μA/l
Where
μ is a constant of permeability of the core
μ = 4π × 10^-7 Tm/A
A is cross sectional area
l is length of coil
L is inductance
Therefore
L = N²μA / l
L=210² × 4π × 10^-7 × 4 × 10^-4 / 0.18
L = 1.23 × 10^-4 H
L = 0.123 mH
B. Self induce EMF ε?
EMF is given as
ε = -Ldi/dt
Since rate of decrease of current is 120 A/s
Then, di/dt = —120A/s, since the current is decreasing
Then,
ε = -Ldi/dt
ε = - 1.23 × 10^-4 × -120
ε = 0.01478 V
ε ≈ 0.015 V
Answer:
Explanation:
Case-A
Block weight 
Friction Force 
and friction force is

where N=normal reaction (Usually equals to weight)


Case-B
Block weight 
Friction Force 



Case-C
Block weight 
Friction Force 



Answer:
Direction of force towards the center and string apply the force.
Explanation:
Lets take
Mass of yo-yo =m
Length of string = L
Angular speed = ω
The radial acceleration a = ω² L
Then the radial force on the yo yo given as
F = m ω² L
Then this radial force act towards the center of the circle formed by yo- yo.The force exerted by string.
So the direction of force towards the center and string apply the force.