Answer:
2 minutes or 120 seconds
Explanation:
The answer is 2 minutes or 120 seconds because 36 km is 36000 m and 36000 divided by 300 is 120, so the answer is 120 seconds, and converted to 2 minutes. Hope it helps!
A ) The displacement:
d = v o t - (gt²) / 2 =
= 19.6 m/s × 1 s - ( 9.8 m/s² x 1 s² ) / 2 =
= 19.6 m - 4.9 m = 14.7 m
b ) v = v o - g t
0 = 19.6 m/s - 9.8 t ( when the ball is at the highest point )
9.8 t = 19.6
t = 19.6 : 9.8
t = 2 s
h = v o t - (gt²)/2 = 19.6 x 2 - ( 9.8 x 4 ) / 2 = 39.2 - 19.6
h = 19.6 m
c ) h = gt² / 2
19.6 = 9.8 t²/2
9.8 t² = 39.2
t² = 39.2 : 9.8
t² = 4
t 2 = 2 s ( and we know that t 1 = 2 s )
t = t 1 + t 2 = 2 s + 2 s = 4 s
Base on my research, within 2 hours you have a number of atoms which remain.
N= N0*2^(-t/6.020 = N= N0*2^-0.33223= 07943 N0
So, the number of atoms that are being disintegrated is N0-N=N0*(1-0.79430)=0.2057 N0
It must be equal to 15 mCi = 15*3.7*10^7= 5.55*10^8 atoms
N0= 5.55*10*8/0.2057 = 2.698*10^9 atoms
Therefore, 2.698*10^9 atoms is the number of N0
Answer:
B. 560 J
J. 1.2 m
Explanation:
v = Final velocity = 0
u = Initial velocity = 4 m/s
= Coefficient of friction = 0.7
m = Mass of runner = 70 kg
g = Acceleration due to gravity = 
Kinetic energy is given by
The mechanical energy lost is 560 J
Acceleration is given by
From kinematic equations we get
The runner slides for 1.2 m
Power<span> is the rate of doing work. It is the amount of energy consumed per unit time. Having no direction, it is a scalar quantity. We express it as follows:
P = W / t
where W = Fd
F = mg
Therefore,
P = mgd / t
P = (30)(9.81)(20) / 1 = 5886 W</span>
