By applying the second equation of motion, the speed at which he threw the second stone is equal to 12.10 m/s.
<h3>How to determine the speed?</h3>
First of all, we would calculate the time taken by the first stone to reach a height of 49 meters by applying the second equation of motion as follows:
S = ut + ½gt²
49 = 0(t) + ½ × 9.8 × t²
49 = 4.9t²
t² = 49/4.9
t = √10
t = 3.16 seconds.
Now, we can determine the speed at which he threw the second stone:
<u>Note:</u> Time = 3.16 - 1 = 2.16 seconds.
S = ut + ½gt²
49 = u(2.16) + ½ × 9.8 × 2.16²
49 = 2.16u + 22.86
2.16u = 49 - 22.86
u = 26.14/2.16
u = 12.10 m/s.
Read more on initial speed here: brainly.com/question/19365526
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1) use energy from food
2) get rid of wastes
3) maintain
Answer:
True
Explanation:
Gamma rays and X-rays are made of packets of energy (photons) without mass or charge, with high penetrating power such that they can pass through the human body and impinge on a photographic plate creating an image of the interior of the human body. They electromagnetic radiation of high energy and high frequency that emanate from some natural sources such as cosmic sun rays and radon gas.
Gamma rays and X-rays can be man made by use of man made electronic devices and radioactive elements
Gamma rays and X-rays find use in airport security scanning and imaging services for medical testing.
Answer:
a) attractiva, b) dF = 
, c) F = 
, d) F = -1.09 N
Explanation:
a) q1 is negative and the charge of the bar is positive therefore the force is attractive
b) For this exercise we use Coulomb's law, where we assume a card dQ₂ at a distance x
dF =
where k is a constant, Q₁ the charge at the origin, x the distance
c) To find the total force we must integrate from the beginning of the bar at x = d to the end point of the bar x = d + L
∫ dF = 
as they indicate that the load on the bar is uniformly distributed, we use the concept of linear density
λ = dQ₂ / dx
DQ₂ = λ dx
we substitute
F = 
F = k Q1 λ (
)
we evaluate the integral
F = k Q₁ λ 
F = k Q₁ λ 
we change the linear density by its value
λ = Q2 / L
F =
d) we calculate the magnitude of F
F =9 10⁹ (-4.2 10⁻⁶) 
F = -1.09 N
the sign indicates that the force is attractive
Answer:
E. 3h
Explanation:
We know that
u = 0 m/s.
velocity after t = 1s
v = u+gt = 0+9.81 x 1s= 9.81 m/s
distance covered in 1st sec
= =>> ut+0.5 x g x t²
=>>0 + 0.5x 9.81 x 1 = 4.90m
Let 4.90 be h
distance travelled in 2nd second will now be used
So velocity after t = 1s
=>>1 x t+ 0.5 x g x t²
=>9.81x 1 + 0.5 x 9.81 x 1 = 3 x 4.90
So since h= 4.90
Then the ans is 3x h = 3h
