Answer:
Hipparchus was an ancient Greek who classified stars based on the brightness in 129 B.C. He grouped the brightest stars and ranked them 1 (first magnitude) and dimmest stars as 6 (sixth magnitude). Thus, the smaller numbers indicated brighter stars. Now, the scale extends in negative axis as well. More the negative number, brighter is the star. For example, Sun has magnitude -26.74.
This the apparent magnitude which means the classification is based on the brightness of the star as it appears from the Earth.
Answer:
C
Explanation:
The pattern is adding .5 to the cm every .1 in weight you just continue the table
Answer:
A helium filled balloon floats forwards in a accelerating car because of the pressure difference between the front and the back of the car. When the car is accelerating, the air moves relitive to the car and the consequence is that the pressure in the back is slightly higher than in the front; which results in net force in forward direction.
hit that heart please leave brainliest and let me know if want me to answer or explain it in a different way :)
Answer: My initial velocity is 5 m/s.
Explanation:
In this case, momentum can be conserved.
initial momentum = final momentum
Since both the bodies come to rest after collision,
Final momentum = 0
Let my velocity be v, and mass, m1 = 60 kg
Friend's mass, m2 = 100 kg
Friend's velocity, v2 = 3 m/s
Intial momentum = m1v + m2v2
= 60v + 300
Conserving momentum,
60v + 300 = 0
v= -5 m/s
( Negative sign indicates that me and my friend are moving in opposite directions that is towards each other)
Answer:
(a) 2.542 cm
(b) 272.7°C
Explanation:
diameter, d = 2.540 cm
T1 = 20°C
α = 11 x 10^-6 /°C
(a) Let d' be the diameter.
T2 = 87°C
Use he formula for the areal expansion
A' = A ( 1 + βΔT)
where, β is the coefficient of areal expansion and ΔT is teh rise in temperature, A' be the area at high temperature and A be the area at low temperature.
β = 2 α = 2 x 11 x 106-6 = 22 x 10^-6 /°C
So,
D'^2 = 2.54^2 ( 1 + 22 x 10^-6 x 67)
D' = 2.542 cm
(b) Let the change in temperature is ΔT.
Use the formula for the volumetric expansion
ΔV = V x γ x ΔT
Where, γ = 3 x α = 3 x 11 x 10^-6 = 33 x 10^-6 /°C
0.9/100 = 33 x 10^-6 x ΔT
ΔT = 272.7°C
