Answer:
moving the boxes and the furniture up to the fifth floor.
Explanation:
The work done when moving an object up or down is equal to its change of gravitational potential energy:

where
m is the mass of the object
g is the gravitational acceleration
is the change in height of the object
We have two opposite situations:
1) when an object is moved upward,
is positive, so the work done W is positive as well: this means that we need to do work in order to move the object, because we have to "win" the effect of gravity, which pulls the object downward
2) when an object is moved downward,
is negative, so the work done W is negative as well: this means that we do not need to do work on the object, because it is already done by gravity, which pulls the object downward.
Therefore, more work is done when we are moving the boxes and the furniture up to the fifth floor.
Answer:
x_total = 4.29m
Explanation:
To solve this exercise we must work in parts. Let's use the law of refraction to find the angle of the refracted ray and trigonometry to find the distances.
Let's start by looking for the angles that the laser refracts
n₁ sin θ₁ = n₂ sin θ₂
where n₁ is the air refraction compensation n₁ = 1, n₂ the water refractive index n₂ = 1,333
θ₂ = sin⁻¹ (n₁ sin θ₁/n₂)
θ₂ = sin⁻¹ (1 sin 27 / 1,333)
θ₂ = sin⁻¹ 0.34057
θ₂ = 19.9º
now let's find the distance from the edge of the pool to the point where the ₂lightning strikes the water
tan θ₁ = y₁ / x₁
x₁ = y₁ / tan θ₁
x₁ = 1.49 / tan 27
x₁ = 2,924 m
Now let's look for the waterfall in the water as far as Robin
tan θ₂₂ = y₂ / x₂
x₂ = y₂ / tan θ₂
x₂ = 3.77 / tan 19.9
x₂ = 1,364
the distance from the edge of the pool to Robin is
x_total = x₁ + x₂
x_total = 2,924 + 1,364
x_total = 4.29m
Answer:
why do people hate on people and hate country people. are you country
because they only think about. themselves and they also think that they are always right .
it's my point of view
hope it is helpful to you
Explanation:
This problem bothers elastic collision.
Given data
Mass m1= 25kg
Initial velocity u1= 5m/s
Final velocity v1= 1.5m/s
Mass m2= 35kg
Initial velocity u2=?
Final velocity v2 = 4.5m/s
A. To find the initial velocity of the 35kg car, let us Apply the principle of conservation of energy
m1u1+m2u2= m1v1+m2v2
25*5+ 35*u2= 25*1.5+ 35*4.5
125+35u2= 37.5+157.5
125+35u2=195
35u2= 195-125
35u2= 70
u2= 2m/s
The initial velocity is 2m/s
B. Totally not kinetic energy before impact
KE= 1/2m1u1²+ 1/2m2u2²
KE= (25*5²)/2+ (35*2²)/2
KE= 625/2 +140/2
KE= 312.5+70
KE= 382.5J
Total kinetic energy after impact
KE=1/2m1v1²+ 1/2m2v2²
KE= (25*1.5²)/2 +(35*4.5²)/2
KE= 56.25/2 +708.75/2
KE=28.125 +354.375
KE= 382.5J
We can see that energy is conserved
Kinetic energy before and after impact remains unchanged
Answer:
17.2 s
Explanation:
Power = Energy / Time
50(746) = 6.40×10^5 / Time
Time = <u>17.2s</u>