The correct answer is
b. low frequencies and low energy.
In fact, microwaves and radio waves have frequency up to , which are really low compared, for instance, to the frequency of gamma rays (
). Moreover, the energy of an electromagnetic wave is directly proportional to its frequency:
where h is the Planck constant and f the frequency; therefore, low frequency means also low energy.
Answer:
10 kg
Explanation:
Assuming a frictionless surface, then force F=ma where F is the applied force, m is the mass and a is acceleration. Making m the subject of the formula then
Substituting 100 N for the applied force F and 10 m/s^2 for acceleration a then the value of m will be
Therefore, in terms of kilograms, the bookshelf weighs 10 Kg
Answer:
t = 3.29 seconds
Explanation:
It is given that,
Height of the Eiffel tower is 60 m
Initial speed of a euro, u = 2 m/s
It will move under the action of gravity in the downward direction. Firstly, we can find the final velocity as follows :
Let t is the time taken by the euro to hit the ground. It can be calculated as :
Hence, it will take 3.29 seconds to hit the ground.