Answer:
No
Explanation:
The vertical component of Jack's initial velocity is:
5.0
⋅
sin
30
∘
=
5.0
⋅
1
2
=
2.5
m/s
With gravitational acceleration
9.8
m/s
2
, he will reach the highest point of his trajectory after:
2.5
9.8
≈
0.255
s
The average vertical component of his velocity in that
0.255
s
will be:
1
2
⋅
2.5
=
1.25
m/s
So the highest point of his trajectory will be:
0.255
⋅
1.25
≈
0.32
m
So he will pass approximately
7
cm
above the top of the candle.
The horizontal component of his velocity will be a constant:
5.0
⋅
cos
30
∘
=
5.0
⋅
√
3
2
≈
4.33
m/s
So Jack's trajectory will be substantially longer than it is high and he will spend little time anywhere near above the candle.
22. a - (vf^2 - vi^2)/(2d)
a = (0 - 23^2)/(170)
a = -3.1 m/s^2
23. Find the time (t) to reach 33 m/s at 3 m/s^2
33-0/t = 3
33 = 3t
t = 11 sec to reach 33 m/s^2
Find the av velocuty: 33+0/2 = 16.5 m/s
Dist = 16.5 * 11 = 181.5 meters to each 33m/s speed. Runway has to be at least this long.
24. The sprinter starts from rest. The average acceleration is found from:
(Vf)^2 = (Vi)^2 = 2as ---> a = (Vf)^2 - (Vi)^2/2s = (11.5m/s)^2-0/2(15.0m) = 4.408m/s^2 estimated: 4.41m/s^2
The elapsed time is found by solving
Vf = Vi + at ----> t = vf-vi/a = 11.5m/s-0/4.408m/s^2 = 2.61s
25. Acceleration of car = v-u/t = 0ms^-1-21.0ms^-1/6.00s = -3.50ms^-2
S = v^2 - u^2/2a = (0ms^-1)^2-(21.0ms^-1)^2/2*-3.50ms^-2 = 63.0m
26. Assuming a constant deceleration of 7.00 m/s^2
final velocity, v = 0m/s
acceleration, a = -7.00m/s^2
displacement, s - 92m
Using v^2 = u^2 - 2as
0^2 - u^2 + 2 (-7.00) (92)
initial velocity, u = sqrt (1288) = 35.9 m/s
This is the speed pf the car just bore braking.
I hope this helps!!
The answer to your question is B
When atoms, the basic units of chemical elements, combine into chemical compounds, they form molecules. Organisms have many different kinds of molecules, from water and simple salts to complex molecules such as carbohydrates, fats, proteins, and deoxyribonucleic acid (DNA). One protein, called hemoglobin, carries oxygen in the blood and is what makes blood red. Hemoglobin contains atoms of six different elements—carbon, hydrogen, oxygen, nitrogen, sulfur, and iron.
Rolling friction is less than sliding friction
