Answer:
6.15 s
Explanation:
The period of a simple pendulum is given by the equation

where
L is the length of the pendulum
g is the acceleration of gravity
For the pendulum in this problem,
L = 1.5 m (length)
(acceleration due to gravity on Earth)
Therefore, its period is

And therefore, the time taken for the pendulum to complete 2.5 oscillations is equal to 2.5 times the period:

Imagine you are in a swimming pool 30m deep. Assuming you know that water is denser than air, you would know that the 30m of water above you will carry more weight, and press down on your body. Say you were in a swimming pool 60m deep, you would be sandwiched between 30m of water pressing down on you, and the upthrust created by the 30m of water below you.
In a building 30m up, the pressure will be regulated, as you are in a building. The floor will be strong enough to support the weight of the body, and the body will not recoil into itself.
Answer:
C is the right answer.
Body massager uses electrical energy to move back and forth. In this sense, a motor is being used for the operation
Each piece of magnet has only two poles, one north and one south. So if you break a bar magnet into two halves, the piece initially consisting the north pole at the edge automatically creates the south pole at the break point and the part consisting south pole creates North pole at the edge. So each piece has 2 poles.
Answer:
v = 10 V and E = 2 10³ N/C
Explanation:
The electrical potentials and the electric field at one point are related by the expression
ΔV = - ∫ E. dS
Where the bold indicates vector quantities, E is the electric field and S is the line of displacement of the load, in general displacement is perpendicular to the equipotential lines, which reduces the product scales to the ordinary product.
If the potential difference is the most usual that is V = 10 V, the electric field is
s = 0.5 cm = 0.5 10⁻² m
E = ΔV / S
E = 10/0.5 10⁻²
E = 2 10³ N / C