Answer:

Explanation:
First, we write the equations of motion for each axis. Since the crate is sliding with constant speed, its acceleration is zero. Then, we have:

Where T is the tension in the rope, F is the force exerted by the first worker, f_k is the frictional force, N is the normal force and mg is the weight of the crate.
Since
and
, we can rewrite the first equation as:

Now, we solve for
and calculate it:

This means that the crate's coefficient of kinetic friction on the floor is 0.18.
Answer:
Part a)
T = 0.52 s
Part b)

Part c)

Explanation:
As we know that the particle move from its maximum displacement to its mean position in t = 0.13 s
so total time period of the particle is given as

now we have
Part a)
T = time to complete one oscillation
so here it will move to and fro for one complete oscillation
so T = 0.52 s
Part b)
As we know that frequency and time period related to each other as



Part c)
As we know that
wavelength = 1.9 m
frequency = 1.92 Hz
so wave speed is given as



A. All natural radiation is at a level low enough to be safe
Answer:
Fossil-fueled cars are still outnumbering the alternative and replacement-fueled cars because they are generally cost-effective and are efficient.
Explanation:
<em>Fossil fuels</em> are non-renewable energy that cannot be replenished. Although many people know how harmful using them can be to the environment, still, people continue to buy cars that are powered by it. This is because, <em>using fossil-fueled cars can help you save money</em> compared to using<em> replacement-fueled cars.</em><em> Its engines are also more powerful,</em> which means they can arrive at their destination in just a few minutes. <u>This makes it efficient.</u> The cost of maintaining a fossil-fueled car is less expensive compared to<em> replacement-fueled cars.</em> People are naturally keen when it comes to budgeting, thus, many people still buy cars powered by fossil fuels.