Answer:
I think it is better if you read and shortly write my explanation
Explanation:
simple pendulum with no friction, mechanical energy is conserved. Total mechanical energy is a combination of kinetic energy and gravitational potential energy. As the pendulum swings back and forth, there is a constant exchange between kinetic energy and gravitational potential energy.
Let volume of empty boat be = 100% = 1V
and mass of boat be M
In water 10%, 0.1V of the volume is submerged.
Mass, m of 1200kg increases the submerging from 10%, 0.1V to 70%, 0.7V
M leads to 0.1V boat submerging
boat submerging.
M + 1200kg leads to 0.7V boat submerging.
This is 60%, 0.6 V increase
By comparison
(M+1200kg) * 0.1V = 0.7V * M
0.1M + 120kg = 0.7M
120kg = 0.7M - 0.1M
120kg = 0.6M
M = (120/0.6)kg
M = 200kg.
The mass of the boat is 200kg.
You can solve this by using Newton's First Law or Newton's Second Law.
1) Newton's First Law or Inertia Law states that in the abscense of a net force acting over an object, this will not chage its state of movement, i.e it will remain at rest (if it is no moving) or with uniform movement (if the object is moving).
2) Newton's Second Law: Net force = mass * acceleration => acceleration = net force / mass = 0 / mass = 0.
Zero accelerations means rest or uniform movement.
First Law is implicit in Second Law.
Answer:
30.81°
Explanation:
θ₁ = angle of incidence = 50°
θ₂ = Angle of refraction
n₂ = Refractive index of glass = 1.5
n₁ = Refractive index of air = 1.0003
From Snell's Law
Using Snell's law as:
Angle of refraction= sin⁻¹ 0.5122 = 30.81°.
<h2>Final velocity of man is -0.23 m/s.</h2>
Explanation:
Conservation of linear momentum :
When no external force acts on a system of several interacting particles, the total linear momentum of system is conserved.
Before the Throw ; Man mass (M₁) = 84.1 kg,
Velocity of Man (u₁) = 0 m/s
Book Mass(M₂) = 1.80 kg
Velocity of book (u₂)= 0 m/s
After the throw ; Man mass(M₁) = 84.1 kg
Velocity of Man(V₁) = ?
Book mass(M₂) = 1.80 kg
velocity of book(V₂) = 11.1 m/s
According to conservation of linear Momentum
Initial Momentum = Final Momentum
M₁u₁ +M₂u₂ = M₁v₁ + M₂v₂
84.1 x0 + 1.80 x0 = 84.1 x v₁ + 1.80 x 11.1
0 = 84.1 v₁ + 19.98
v₁ = -19.98 /84.1
= -0.23 m/s
final velocity of man is -0.23 m/s