Answer:
Acceleration due to gravity will be 
Explanation:
We have given length of pendulum l = 55 cm = 0.55 m
It is given that pendulum completed 100 swings in 145 sec
So time taken by pendulum for 1 swing 
We have to find the acceleration due to gravity at that point
We know that time period of pendulum;um is given by

So 

Squaring both side


So acceleration due to gravity will be 
B. How much work can be done in a given time. That’s why it’s measured occasionally I. “Horsepower.” It’s your ability to work fast and far.
Answer:
Part a)

Part B)

Explanation:
As we know that when both the forces are acting on the object in same direction then we will have

as we know that

m = 10.6 kg
now we will have


Now two forces are in opposite direction then we have


Part A)
Now we will have from above two equation

Part B)
Similarly for other force we have

Answer:
The time it takes the ball to fall 3.8 meters to friend below is approximately 0.88 seconds
Explanation:
The height from which the student tosses the ball to a friend, h = 3.8 meters above the friend
The direction in which the student tosses the ball = The horizontal direction
Given that the ball is tossed in the horizontal direction, and not the vertical direction, the initial vertical component of the velocity of the ball = 0
The equation of the vertical motion of the ball can therefore, be represented by the free fall equation as follows;
h = 1/2 × g × t²
Where;
g = The acceleration due gravity of the ball = 9.81 m/s²
t = The time of motion to cover height, h
Then height is already given as h = 3.8 m
Substituting gives;
3.8 = 1/2 × 9.81 × t²
t² = 3.8/(1/2 × 9.81) ≈ 0.775 s²
∴ t = √0.775 ≈ 0.88 seconds
The time it takes the ball to fall 3.8 meters to friend below is t ≈ 0.88 seconds.
Answer:
Option (3)
Explanation:
Nicolaus Copernicus was an astronomer from Poland, who was born on the 19th of February in the year 1473. He played a great role in the field of modern astronomy.
He was the person who contributed to the heliocentric theory. This theory describes the position of the sun in the middle of the universe, and all the planets move around the sun. This theory was initially not accepted, and after about a century it was widely accepted.
This theory describes the present-day motion of the planets around the sun in the solar system. This theory replaced the geocentric theory.
Thus, the correct answer is option (3).