D all of them is the answer. All three can be used to celebrate sporting events
Speed = frequency times wavelength.
40=8xf
f = 5 Hz or cycles per second.
Answer:
Average velocity = 18 m/s
Explanation:
Given the following data;
Initial velocity = 10m/s
Acceleration = 2m/s²
Time = 4 seconds
To find the average velocity, we would use the first equation of motion;
Where;
V is the final velocity.
U is the initial velocity.
a is the acceleration.
t is the time measured in seconds.
Substituting into the equation, we have;
V = u + at
V = 10 + 2*4
V = 10 + 8
V = 18 m/s
B) Light slows down when it passes into a denser medium.
I'm not sure what your question is. But, the half life is the amount of time required for half the material to decay. For U238 this is 4.5 billion years, whilst for Fr-223 (Francium) its about 22 minutes. To calculate the time for something to decay you need to use the equation:
Mass (after time t) = Mass (initial) * (0.5)^(time/half life)
Hope this helps