It is D as u dont need a stop watch aft that
Answer:
27.22 m/s
Explanation:
Let the speed of clay before impact is u.
the speed of clay and target is v after impact.
use conservation of momentum
momentum before impact momentum after impact
mass of clay x u = (mass of clay + mass of target) x v
100 x u = (100 + 500) x v
u = 6 v .....(1)
distance, s = 2.1 m
μ = 0.5
final velocity is zero. use third equation of motion
v'² = v² + 2as
0 = v² - 2 x μ x g x s
v² = 2 x 0.5 x 9.8 x 2.1 = 20.58
v = 4.54 m/s
so by equation (1)
u = 6 x 4.54 = 27.22 m/s
thus, the speed of clay before impact is 27.22 m/s.
Answer:
Red giant or super giant → very cool but very luminous
→ found in the upper right of the H-R diagram.
Main sequence →The majority of stars in our galaxy
→ Sun, for example
→ a very hot and very luminous star
White dwarfs → very hot but very dim
→ not much larger in radius than earth
Explanation:
Giant:
When the stars run out of their fuel that is hydrogen for the nuclear fusion reactions then they convert into Giant stars.That's why they are very cool. Giant stars have the larger radius and luminosity then the main sequence stars.
Main Sequence:
Stars are called main sequence stars when their core temperature reaches up to 10 million kelvin and their start the nuclear fusion reactions of hydrogen into helium in the core of the star. That is why they are very hot and luminous. For example sun is known as to be in the stage of main sequence as the nuclear fusion reactions are happening in its core.
White dwarfs:
When the stars run out of their fuel then they shed the outer layer planetary nebula, the remaining core part that left behind is called as white dwarf. It's the most dense part as the most of the mass is concentrated in this part.
Answer:
Explanation:
a ) After the attainment of terminal speed , object takes 4.5 s to cover a distance of 2 m
So terminal speed V = 2 / 4.5
= .444 m /s
When it attains terminal speed , acceleration becomes zero
0 = g - B x .444
B = 22.25 s⁻¹
b ) At t = 0 , v = 0
a = g - B v
a = g at t = 0
c ) When v = .15
a = g - 22.25 x .15
= 9.8 - 3.31
= 6.5 m /s²
Answer:
60.025m.
Explanation:
S= ut + at^2/2 (2nd equation of motion)
S= 0 + (9.8)(3.5)^2 /2 (free fall case, initial velocity = 0)
S = 4.9 x 12.25
S= 60.025 m.
Disclaimer: did math in my head, so you better double check with a calculator.