Speed can be thought of as the rate at which an object covers distance. ... Speed has the dimensions of distance divided by time. The SI unit of speed is the metre per second, but the most common unit of speed in everyday usage is the kilometre per hour or, in the US and the UK, miles per hour........?
Answer:
6.7 m/s^2
Explanation:
The formula of acceleration is:

where
is acceleration,
is velocity and
is time.
means final velocity.
means initial velocity,
means final time and
means initial time.
We are given that the Firebird travels at velocity of 0 to 60 mph in four seconds. Therefore:
- Our initial velocity starts at 0 mph.
- Our final velocity is at 60 mph.
- Our initial time is 0 second.
- Our final time is 4 seconds.
Since it travels to the east then our vector will be positive. However, acceleration has to be in m/s^2 unit (Sl unit) so we'll have to convert from mph (miles per hours) to m/s (meters per second) first.
We know that:
- A mile equals to 1609.344 meters.
- An hour equals to 60 minutes which a minute equals to 60 seconds. So 60 minutes will equal to 3600 seconds.
Now we divide 1609.344 by 3600 to find a unit rate of m/s:

Now multiply 0.44704 m/s by 0 and 60 to get velocity in m/s unit:
- Initial velocity = 0 m/s
- Final velocity = 60 * 0.44704 = 26.82 m/s
Time is already in second so no need for conversion. Substitute known information in the formula:

Therefore, the Firebird will accelerate at the rate of 6.7 m/s^2.
Answer:
waves that are created as a result of vibrations between an electric field and a magnetic field
As the surface given is a smooth surface, we can use specular reflection. According to the law of specular reflection, the angle of incidence equals the angle of reflection, so it will also be 40°. Answer is A.