Answer:
Explanation:
The equation or formula for velocity is similar to speed. To figure out velocity, you divide the distance by the time it takes to travel that same distance, then you add your direction to it.
Answer:
a) v = √ 2gL abd b) θ = 45º
Explanation:
a) for this part we use the law of conservation of energy,
Highest starting point
Em₀ = U = mg h
Final point. Lower
Em₂ = ½ m v²
Em₀ = Em₂
m g h = ½ m v²
v = √2g h
v = √ 2gL
b) the definition of power is the relationship between work and time, but work is the product of force by displacement
P = W / t = F. d / t = F. v
If we use Newton's second law, with one axis of the tangential reference system to the trajectory and the other perpendicular, in the direction of the rope, the only force we have to break down is the weight
sin θ = Wt / W
Wt = W sin θ
This force is parallel to the movement and also to the speed, whereby the scalar product is reduced to the ordinary product
P = F v
The equation that describes the pendulum's motion is
θ = θ₀ cos (wt)
Let's replace
P = (W sin θ) θ₀ cos (wt)
P = W θ₀ sint θ cos (wt)
We use the equation of rotational kinematics
θ = wt
P = Wθ₀ sin θ cos θ
Let's use
sin 2θ = 2 sin θ cos θ
P = Wθ₀/2 sin 2θ
This expression is maximum when the sine has a value of one (sin 2θ = 1), which occurs for 90º,
2θ = 90
θ = 45º
Answer:
<h2>Rate of heat transfer from the body of the person is given as</h2><h2>
![\frac{dQ}{dt} = 800 J/s](https://tex.z-dn.net/?f=%5Cfrac%7BdQ%7D%7Bdt%7D%20%3D%20800%20J%2Fs)
</h2>
Explanation:
As we know that the rate of heat transfer due to thermal conduction is given as
![\frac{dQ}{dt} = \frac{kA(T_2 - T_1)}{x}](https://tex.z-dn.net/?f=%5Cfrac%7BdQ%7D%7Bdt%7D%20%3D%20%5Cfrac%7BkA%28T_2%20-%20T_1%29%7D%7Bx%7D)
so we have
k = 0.04 W/m C
![A = 1.6 m^2](https://tex.z-dn.net/?f=A%20%3D%201.6%20m%5E2)
![x = 2\times 10^{-3} m](https://tex.z-dn.net/?f=x%20%3D%202%5Ctimes%2010%5E%7B-3%7D%20m)
![\frac{dQ}{dt} = \frac{(0.04)(1.6)(36 - 11)}{2 \times 10^{-3}}](https://tex.z-dn.net/?f=%5Cfrac%7BdQ%7D%7Bdt%7D%20%3D%20%5Cfrac%7B%280.04%29%281.6%29%2836%20-%2011%29%7D%7B2%20%5Ctimes%2010%5E%7B-3%7D%7D)
![\frac{dQ}{dt} = 800 J/s](https://tex.z-dn.net/?f=%5Cfrac%7BdQ%7D%7Bdt%7D%20%3D%20800%20J%2Fs)
<h3>formula of speed is distance/time</h3><h3>so</h3><h2>140/2.5</h2><h2>= 56</h2><h2>the answer should be </h2><h2>56 km/h</h2>
The coefficient of friction is 0.213
Explanation:
We start by writing the equation of the forces along the directions parallel and perpendicular to the incline. We have:
Perpendicular direction:
(1)
where
N is the normal reaction of the plane
is the component of the weight perpendicular to the plane, with
m is the mass
g = 9.8 m/s^2 the acceleration of gravity
is the angle of the incline
Parallel direction:
(2)
where
:
is the component of the weight parallel to the slope
is the force of friction, where
is the coefficient of friction
N is the normal reaction
a is the acceleration
In this case, the skier is moving at constant speed, so its acceleration is zero and the equation becomes:
(2)
From (1) we find
And substituting into (2)
Solving for
,
Learn more about slope and force of friction here:
brainly.com/question/5884009
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