Answer:
A. 4,9 m/s2
B. 2,0 m/s2
C. 120 N
Explanation:
In the image, 1 is going to represent the monkey and 2 is going to be the package. Let a_mín be the minimum acceleration that the monkey should have in the upward direction, so the package is barely lifted. Apply Newton’s second law of motion:
If the package is barely lifted, that means that T=m_2*g; then:
Solving the equation for a_mín, we have:
Once the monkey stops its climb and holds onto the rope, we set the equation of Newton’s second law as it follows:
For the monkey: 
For the package: 
The acceleration a is the same for both monkey and package, but have opposite directions, this means that when the monkey accelerates upwards, the package does it downwards and vice versa. Therefore, the acceleration a on the equation for the package is negative; however, if we invert the signs on the sum of forces, it has the same effect. To be clearer:
For the package: 
We have two unknowns and two equations, so we can proceed. We can match both tensions and have:
Solving a, we have
We can then replace this value of a in one for the sums of force and find the tension T:
Answer:
Scientists have studied eclipses since ancient times. Aristotle observed that the Earth's shadow has a circular shape as it moves across the moon. He posited that this must mean the Earth was round. Another Greek astronomer named Aristarchus used a lunar eclipse to estimate the distance of the Moon and Sun from Earth
Explanation:
Magnet: It has two poles: South pole and North pole.
Magnetic field lines are stronger near the poles of the magnet.
Same poles repel each other. There is a magnetic force of repulsion between the same poles. North- North poles repel each other.
Unlike poles attract each other. There is magnetic force of attraction between the opposite poles. South- North poles attract each other.
Mono poles cannot exist.
From the given statements, the magnetic poles are described by:
A north pole must exist with a south pole.
Two south poles placed near each other will repel each other.
A north pole and a south pole placed near each other will attract each other.
Explanation:
The general equation of an AC current is given by :
Where
I₀ is the peak value of current
is angular frequency
So,
We know that,
So, the frequency is 50 Hz and the maximum rms value of current is 14.14 A.
Gravity causes a falling object to fall 9.8 m/s faster every second it falls.
Kenny's book started out with no speed when it was dropped.
1.5 sec later, it was falling at (9.8 x 1.5) = 14.7 m/s .
During the fall, its average speed was 1/2(0 + 14.7) = 7.35 m/s .
Distance it covered = (average speed) x (time) =
(7.35 m/s) x (1.5 sec) = 11.025 m
