Answer:
h = height of the hotel room from the ground floor = 237.4m
Explanation:
Change in Potential Energy of tourist = ΔPE = PE2 – PE1 = mgh
PE1 is the potential energy of tourist at the ground floor
PE1 is the potential energy of tourist at the top (hotel room)
Given
PE1 = − 2.01 × 10⁵ J
PE2 = 0J
PE2 – PE1 = mgh
0 – (− 2.01 × 10⁵ J) = mgh
2.01 × 10⁵ J = 86.4×9.8×h
h = 2.01 × 10⁵/(86.4×9.8) = 237.4m
Answer:
1) D, 2) D, 3) B, 4) B, 5) C
Explanation:
You are asked to select the correct answer
1) The conservation of energy is one of the most important principles of physics that allows solving countless problems in life.
the correct answer is D
2) when a body falls, the gravitational potential energy is transformed into kinetic energy and both are transformed into thermal energy
the correct answer is D
3) When the gravitational potential energy is maximum, the kinetic energy is minimum and when the kinetic energy is maximum, the gravitational energy is minimum.
Correct answer B
4) speed is defined by
v = x / t
so the correct answer is B in the SI system
5) when we repeat a measurement several times, the random or statistical errors decrease, therefore the confidence of the measurement increases.
The correct answer is C
Answer:
the current value is 
Explanation:
The computation of the value of the current is given below:
Hence, the current value is
<span>net work = change in kinetic energy
for Block B, we just have the force from block A acting on it
F(ab)d= .5(1)vf² - .5(1)(2²)
F(ab)d= .5vf² - 2
Block A, we have the force from the hand going in one direction and the force of block B on A going the opposite direction
10-F(ba)d = .5(4)vf² - .5(4)(2²)
10-F(ba)d = 2vf² - 8
F(ba)d = 18 - 2vf²
now we have two equations:
F(ba)d = 18 - 2vf²
F(ab)d= .5vf² - 2
since the magnitude of F(ba) and F(ab) is the same, substitute and find vf (I already took into account the direction when solving for F(ab)
10-.5vf² + 2 = 2vf² - 8
12 - .5vf² = 2vf² - 8
20 = 2.5vf²
vf² = 8
they both will have the same velocity
KE of block A= .5(4)(2.828²) = 16 J
KE of block B=.5(1)(2.828²) = 4 J</span>
C. Newton’s Third Law of Motion.
Because...
Newtons third law implies conversation of momentum it can also be seen as following from the second law: when one object pushes a second object at some point of contact using an applied force, there must be an equation of opposite force from the second object that cancels the applied force. Otherwise, there would be a nonzero net force on a massless point which, by the second law, would accelerate the point of contact by an infinite amount.
