M1(mass of wood) = 4 kg
M2(mass of water) = 3 kg
V1(volume of wood) = 2 * V2(volume of water )
Density = mass/volume ======= volume = mass/density
Density of water is 1 kg/m3
V2 = M2/density of water
V2 = 3 kg/m3/1kg/m3
V2 = 3 m3
V1(volume of wood) = 2 * V2
V1 = 2 * 3m3
V1 = 6m3
Density of wood = M1 ( mass of wood)/ V1(volume of wood)
Density of wood = 4 kg/ 6m3 = 2/3 kg/m3
Answer:
a) 27.2 V
b)27.2 V
Explanation:
Charge of the electron =charge of the proton = q = 1.6 × 10⁻¹⁹ C
Radius = r = 0.53×10⁻¹⁰ m
Electric Potential = V = k q/r
k = 9 ×10⁹ N m²/C² = Coulomb's constant.
V = (9 ×10⁹)(1.6 × 10⁻¹⁹)/( 0.53×10⁻¹⁰) = 27.2 V
b) Potential Energy of the electron = k q × q / r
= [(9 ×10⁹)(1.6 × 10⁻¹⁹)(1.6 × 10⁻¹⁹) / (0.53×10⁻¹⁰)] / (1.6 × 10⁻¹⁹) eV,
since 1 electron volt = (1.6 × 10⁻¹⁹)joules
= 27.2 eV
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:
The normal force applied by block on the ground is (mg - F cosФ)
Explanation:
<em>Lets explain how to solve the problem</em>
At first you must distribute the force F into two components
<em>Vertical</em> component which is <em>F cosФ</em>
<em>Horizontal</em> component which is <em>F sinФ</em>
The block is in equilibrium, that means sum of forces acting on the
block is zero
So the upward forces equal the downward forces
Normal reaction force R applied by block on the ground and the
vertical component of F both are upward forces
The weight of the block is downward force
The normal reaction force R plus the vertical component of F is
equal to the weight
<em>R + F cosФ = W</em>
W = mg, where g is acceleration of gravity and m is the mass of
the block
<em>R + F cosФ = mg</em>
Subtract F cosФ from both sides
<em>R = mg - F cosФ</em>
<em></em>
The normal force applied by block on the ground is (mg - F cosФ)