Answer:
D lower energy waves is most likely the safest if one is exposed to.
Answer:
Final speed of the crate is 15 m/s
Explanation:
As we know that constant force F = 80 N is applied on the object for t = 12 s
Now we can use definition of force to find the speed after t = 12 s

so here we know that object is at rest initially so we have


Now for next 6 s the force decreases to ZERO linearly
so we can write the force equation as

now again by same equation we have



put t = 6 s



Answer:
(a) T = 0.015 N
(b) M = 1.53 x 10⁻³ kg = 1.53 g
Explanation:
(a) T = 0.015 N
First, we will find the speed of waves:

where,
v = speed of wave = ?
f = frequency = 120 Hz
λ = wavelength = 6 cm = 0.06 m
Therefore,
v = (120 Hz)(0.06 m)
v = 7.2 m/s
Now, we will find the linear mass density of the coil:

where,
μ = linear mass density = ?
m = mass = 1.45 g = 1.45 x 10⁻³ kg
l = length = 5 m
Thereforre,

Now, for the tension we use the formula:

<u>T = 0.015 N</u>
<u></u>
(b)
The mass to be hung is:

<u>M = 1.53 x 10⁻³ kg = 1.53 g</u>
Answer:
The total volume of the air is 1000 cubic centimeters.
Explanation:
Since the bicycle pump and the bicycle tyre have the same pressure, then the total volume of the air is the sum of the volume of each element, then we translate this into the following artihmetical expression:


The total volume of the air is 1000 cubic centimeters.
Answer:
The skidding distance would be doubled
Explanation:
When the truck applies the brakes and slows down, its motion is a uniformly accelerated motion, so its skidding distance can be found by using the suvat equation

where
v = 0 is the final velocity (zero since the truck comes to a stop)
u is the initial velocity
a is the acceleration
s is the skidding distance
The acceleration can also be written as

where F is the force applied by the brakes and m the mass of the truck. Substituting into the previous equation,

We see that the skidding distance is proportional to the mass: therefore, if the mass of the truck is doubled, the skidding distance will double as well.