u = 0.077
Explanation:
Work done by friction is
Wf = ∆KE + ∆PE
-umgx = ∆KE,. ∆PE =0 (level ice surface)
-umgx = KEf - KEi = -(1/2)mv^2
Solving for u,
u = v^2/2gx
= (12 m/s)^2/2(9.8 m/s^2)(95 m)
= 0.077
Answer:
c) 3176 J
Explanation:
mass of 125 popcorn = 125 x .0001 = . 0125 kg
increase in temperature = 175 - 21 = 154°C
specific heat of popcorn = 1650
heat required to increase temperature
= mass of popcorn x increase in temperature x specific heat
= .0125 x 154 x 1650
= 3176.25 J
Assuming north as positive direction, the initial and final velocities of the ball are:
(with negative sign since it is due south)
the time taken is
, so the average acceleration of the ball is given by
And the positive sign tells us the direction of the acceleration is north.
I think it would be Newton’s second law
Answer:
Star A is brighter than Star B by a factor of 2754.22
Explanation:
Lets assume,
the magnitude of star A = m₁ = 1
the magnitude of star B = m₂ = 9.6
the apparent brightness of star A and star B are b₁ and b₂ respectively
Then, relation between the difference of magnitudes and apparent brightness of two stars are related as give below:
The current magnitude scale followed was formalized by Sir Norman Pogson in 1856. On this scale a magnitude 1 star is 2.512 times brighter than magnitude 2 star. A magnitude 2 star is 2.512 time brighter than a magnitude 3 star. That means a magnitude 1 star is (2.512x2.512) brighter than magnitude 3 bright star.
We need to find the factor by which star A is brighter than star B. Using the equation given above,
Thus,
It means star A is 2754.22 time brighter than Star B.