This is the reason why dimensional analysis is very important. It is a technique used that only involves operations with units. You disregard the quantities first. The concept is to make sure that the final answer of your calculations must be consistent of what is asked. Similar units are cancelled when they appear both on the numerator and denominator side. If the mathematicians used this, they could've prevented the crash from happening. What good would the calculations bring if you are not consistent with the units?

7 0

3 years ago

A motor spins up the flywheel with a constant torque of 50 n⋅m. how long does it take the flywheel to reach top speed?

dimulka [17.4K]

A motor spins upward the flywheel with a persistent torque of 50N⋅m.

What time does it take the flywheel to get to the top speed?
From the equation:
Tj = J*dω/dt

you can get the two equations:
Δt1= J1*Δω/Tj = 240*125.66/50 = 603.17 sec
Δt2= J2*Δω/Tj = 120*125.66/50 = 301.58 sec

6 0

4 years ago

A light ray in glass (n=1.5) hits the air-glass interface at an angle of 10 degrees from the normal. What angle from the normal

jekas [21]

Answer:

The angle from the normal is 15.1°.

Explanation:

We can find the angle by using Snell's law:

$n_{1}sin(\theta_{1}) = n_{2}sin(\theta_{2})$

Where:

n₁: is the first medium (glass) = 1.5

n₂: is the second medium (air) = 1.0

θ₁: is the first angle (in the glass) = 10°

θ₂: is the second angle (in the air) =?

$\theta_{2} = arcsin(\frac{n_{1}sin(\theta_{1})}{n_{2}}) = arcsin(\frac{1.5*sin(10)}{1.0}) = 15.1 ^{\circ}$

Therefore, the angle from the normal is 15.1°.

I hope it helps you!

7 0

3 years ago