Also 4 sec. Without air resistance, all objects fall with the same acceleration, and reach bottom in the same amount of time.
Answer:
A
Explanation:
Electromagnet: It is a temporary magnet. It consists of wrapping coils around iron core and the power source. When the current passes through the coils around the iron core then it will get magnetized. The domains of the electromagnet gets aligned.
As long as the current passes through it, it will get magnetized. It will loose its magnetism easily when the power is switched off.
In the electromagnet, the strength of the magnetism can be increased or decreased. The poles of the electromagnet are not fixed.
Answer:
40.5 m/s
Explanation:
Given:
v₀ = 0 m/s
a = 16.4 m/s²
Δx = 50 m
Find: v
v² = v₀² + 2aΔx
v² = (0 m/s)² + 2 (16.4 m/s²) (50 m)
v = 40.5 m/s
The half-life of a substance describes the time in which it takes for half of the radioactive isotope to decay into another form. In your question, it says that the half life of radon-222 is 3.82 days; in a 100g sample of radon, 3.82 days pass and 50g of that isotope is left.
7.64 days is the equivalent to two half lives (7.64/3.82), so only half of half of 100%, or 25%, of the isotope would remain. The answer is D
Hope that helps
