-- Equations #2 and #6 are both the same equation,
and are both correct.
-- If you divide each side by 'wavelength', you get Equation #4,
which is also correct.
-- If you divide each side by 'frequency', you get Equation #3,
which is also correct.
With some work, you can rearrange this one and use it to calculate
frequency.
Summary:
-- Equations #2, #3, #4, and #6 are all correct statements,
and can be used to find frequency.
-- Equations #1 and #5 are incorrect statements.
Answer:
The velocity of the truck after this elastic collision is 15.7 m/s
Explanation:
It is given that,
Mass of the car, 
Mass of the truck, 
Initial velocity of the car,
Initial velocity of the truck, u₂ = 0
After the collision the velocity of the car is, v₁ = -11 m/s
Let v₂ is the velocity of the truck after this elastic collision. Using the conservation of momentum as :

So, the velocity of the truck after this elastic collision is 15.7 m/s. Hence, the correct option is (c).
The fast lap is irrelevant to the question, because it didn't happen
until after the 9 laps that you're interested in.
To be perfectly technical about it, we don't actually have enough
information to answer the question. You told us her average speed
for 10 laps, but we don't know anything about how her speed may
have changed during the whole 10 laps. For all we know, maybe
she took a nap first, and then got up and drove 10 laps at the speed
of 125 metres per second. That would produce the average speed
of 12.5 metres per second and we would never know it Why not ?
That's only 280 miles per hour. Bikes can do that, can't they ?
IF we can assume that Amy maintained a totally steady pace through
the entire 10 laps, then we could say that her average for 9 laps was
also 12.5 metres per second.
Answer:
The total distance is 16.9 m
Explanation:
We understand work in physics as certain force exerted through certain distance. To reach that point below the water, the work done by the diver must be equal to the work done by the water's force of resistance. Therefore, we determine both work expressions and we solve the equation for the diver distance, which is the total distance between the diving board and the stopping point underwater.
