Answer:
3.33 seconds
Explanation:
We can use the velocity formula [ v = u + at ] to solve.
Find the value "u".
135km/h -> 135km*1000m/3600s -> 37.5m/s
Find the value "v".
75km/h -> 75km*1000m/3600s -> 20.83m/s
Keep in mind we are dealing with "deceleration" so when we input 5.0m/s into the formula, it will be a negative value.
Now, find "t" which is the value we aren't given with the values we're given in the question.
20.83 = 37.5 - 5t
-16.67 = -5t
3.33 = t
Best of luck!
There would be infinite acceleration, and the body would have no mass <span />
I think this is vectors. Sketch the two vectors A and B on the x axis and then find their magnitudes using cosine... i would like to know if i am correct.
Answer:
The answer is <em>e.2</em>
Explanation:
We should make use of Snell's refractive law. The arriving wave has a certain velocity at T in a medium, then instantly it reaches a medium (same composition) at T' where velocity would either decrease or increase.
When the incidence angle is 30 °, and we want to make the refraction angle 90 ° such that no sound passes through the barrier (this would be named total internal refraction), so we want the second medium to be "faster" than in the first.
<em>The steps are in the image attached:</em>
Sun is the main source of energy