Answer:
21.8 m/s
Explanation:
At the top of the hill (crest), there are two forces acting on the motorcycle:
- The reaction force of the road, N (upward)
- The force of gravity, mg (downward)
Since the motorcycle is moving by circular motion, the resultant of these forces will give the centripetal force, so:

where the direction of the weight (mg) is equal to that of the centripetal force, and where
m is the mass of the cycle
g = 9.8 m/s^2 is the acceleration of gravity
v is the speed
r = 48.6 is the radius of the hill
The cycle loses contact with the road when the reaction force becomes zero:
N = 0
Substituting into the equation, we therefore find the maximum speed that is allowed for the cycle before losing constact:

Answer:

Explanation:
Given that,
The speed of an electromagnetic wave traveling in a transparent nonmagnetic substance is given by :

Where
k is the dielectric constant of the substance.
v is the speed of light in water


So, the speed of light in water is 
Answer:
(A) She needs to move the decimal point by 3 places
<em>It's a test on Geography!
</em>
Average speed is defined as total distance moved in total interval of time
so it is given as

now here is we show distance by "d" and time by"t"
then we will have mathematical expression as follows
