Answer:
The total energy of the object does not change is the true statement.
Explanation:
1. The force applied to the object is perpendicular to the movement so doesn't work on it, assuming the table is at the same height in all of its points the only energy we have to analyze is the kinetic energy , because the table top is frictionless by Newton's first law the velocity (v) doesn't change so the kinetic energy is constant and the total energy too.
2. There's no friction in this situation
3. As stated on 1. because the applied force is perpendicular to the movement of the object, there force doesn't work on it.
4. There are over one force on the object, the weight and the normal force table top exerts to the object.
So the only true statement is 1.
Answer:
B) trenches
Explanation:
New oceanic crust is formed and pushes the old oceanic crust down into a trench.
Answer:
The crate was being lifted by a height of 1.48 meters.
Explanation:
In an attempt o move a crate;
Force applied = 2470 N
Work done by the force = 3650 J
We know that the work done is defined as the force used to move an object to a distance.
Given the Force used and the work done by that Force, we need to find out the distance the crate was lifted to.
Work done is defined as:
Work = Force*distance covered in the direction of the force
3650 = 2470*distance
distance = 3650/2470
distance = 1.48 meters
Answer:
The speed doubles.
Explanation:
The speed of a wave in a string is:
v = √(T / ρ)
where T is the tension and ρ is the linear density (mass per length).
If T is held constant, and ρ decreases by 1/4, then:
v = √(T / (ρ/4))
v = √(4T / ρ)
v = 2√(T / ρ)
The speed doubles.
Answer:
Correct answer: V₂ = 1.79 m/s
Explanation:
Given:
m₁ = 32 kg the mass of the first student
V₁ = 2.4 m/s speed of the first student after pushing
m₂ = 43 kg the mass of the second student student
V₂ = ? speed of the second student after pushing
I₁ = m₁ · V₁ impulse of the first student
I₂ = m₂ · V₂ impulse of the second student
Under the law of impulse maintenance, the total impulse of an object must be constant over time.
Since the total impulse before pushing was equal to zero it must be afterwards.
I₁ + I₂ = 0 ⇒ I₂ = - I₁ ⇒ V₂ = - V₁
Given that the impulses are vectors a sign minus ahead of the first pulse mean, they are opposite directions.
m₂ · V₂ = m₁ · V₁ ⇒ V₂ = (m₁ · V₁) / m₂ = (32 · 2.4) / 43 = 1.79 m/s
V₂ = 1.79 m/s
God is with you!!!