Answer:
The minimum compression is 
Explanation:
From the question we are told that
The mass of the block is 
The spring constant is 
The coefficient of static friction is 
For the the block not slip it mean the sum of forces acting on the horizontal axis is equal to the forces acting on the vertical axis
Now the force acting on the vertical axis is the force due to gravity which is mathematically given as

And the force acting on the horizontal axis is force due to the spring which is mathematically represented as

where x is the minimum compression to keep the block from slipping
Now equating this two formulas and making x the subject

substituting values we have


Answer:
The speed of the sled is 3.56 m/s
Explanation:
Given that,
Mass = 2.12 kg
Initial speed = 5.49 m/s
Coefficient of kinetic friction = 0.229
Distance = 3.89 m
We need to calculate the acceleration of sled
Using formula of acceleration

Where, F = frictional force
m = mass
Put the value into the formula




We need to calculate the speed of the sled
Using equation of motion

Where, v = final velocity
u = initial velocity
a = acceleration
s = distance
Put the value in the equation



Hence, The speed of the sled is 3.56 m/s.
Answer: The average velocity is -0.965m/s
Explanation: The first step is to calculate the two velocities is both directions. A velocity is a distance per unit time.
V=d/ t
=-5.7/2.1
=-2.7m/s
For the other direction the velocity is
V=7.3/9.5
=0.77m/s
The average velocity the add the velocities and divide them by 2.
V=-2.7+0.77/2
V= 0.965m/s
Answer:

Explanation:
The magnetic field strenght on the z-axis at a distance d from the center is,

Our values are:

Replacing,


Explanation:
By the statement, Efficiency of a machine is 60% it is meant that 'The work output is 60% of the work input'. If you apply 100J of energy for a machine, it will be able to life load of 60 J only