Hey,
I think the answer's are 1,3
Hope this helpss
~Girlygir101~
Answer:
a) v = √ 2gL abd b) θ = 45º
Explanation:
a) for this part we use the law of conservation of energy,
Highest starting point
Em₀ = U = mg h
Final point. Lower
Em₂ = ½ m v²
Em₀ = Em₂
m g h = ½ m v²
v = √2g h
v = √ 2gL
b) the definition of power is the relationship between work and time, but work is the product of force by displacement
P = W / t = F. d / t = F. v
If we use Newton's second law, with one axis of the tangential reference system to the trajectory and the other perpendicular, in the direction of the rope, the only force we have to break down is the weight
sin θ = Wt / W
Wt = W sin θ
This force is parallel to the movement and also to the speed, whereby the scalar product is reduced to the ordinary product
P = F v
The equation that describes the pendulum's motion is
θ = θ₀ cos (wt)
Let's replace
P = (W sin θ) θ₀ cos (wt)
P = W θ₀ sint θ cos (wt)
We use the equation of rotational kinematics
θ = wt
P = Wθ₀ sin θ cos θ
Let's use
sin 2θ = 2 sin θ cos θ
P = Wθ₀/2 sin 2θ
This expression is maximum when the sine has a value of one (sin 2θ = 1), which occurs for 90º,
2θ = 90
θ = 45º
Answer:
26280
Explanation:
In current time, good telescope can measure redshift to a galaxy in 10 minutes.
Thus, in one year that has on an average 365 days, the total time taken to measure redshifts is = ( 365 *12 *60) minute
= 262800 minutes .
Hence, the number of redshifts observed in a year = (262800/10) = 26280
Alkali metals
Nonmetals
<span>Halogens</span>
