Answer:
a. 8p
Explanation:
We are given that
Radius of hollow sphere , R1=R
Density of hollow sphere=
After compress
Radius of hollow sphere, R2=R/2
We have to find density of the compressed sphere.
We know that


Therefore,
Volume of sphere=
Using the formula



Hence, the density of the compressed sphere=
Option a is correct.
Answer:
10s
Explanation:
If it took Beatrice 25 seconds to complete the race
Distance = 100 meter
Beatrice speed = 100/25
= 4m/s
If Alice runs at a constant speed and crosses the finish line $5$ seconds, she must have completed the race in 20s (25 -5).
Her speed where constant
= 100/20
= 5 m/s
It would take Alice
= 50/5
= 10s
It would take Alice 10s to run $50$ meters.
Here we can use coulomb's law to find the force between two charges
As per coulombs law
]tex]F = \frac{kq_1q_2}{r^2}[/tex]
here we have




now by using the above equation we have


so here the force between two charges is of above magnitude and this will be repulsive force between them as both charges are of same sign.
Answer:
Explanation:
Potential energy is the energy of a body due to is virtue of rest.
Potential energy is given as mgh
g is a constant and it is 9.81m/s²
And also the mass of the body is given as 1.3kg
Now the height of the body is
He took a book to a storey building of height 26m
He still holds the book 151 cm (1.51m) above the house.
The house is on an altitude of 1609m from the sea level.
Total Ug with out the sea level is
Ug=mgh
Ug=1.3 × 9.81 ×(26+1.51)
Ug=350.84J
Then, the potential energy due to the sea level is given as
Ug=mgh
Where g = 1/6371 m/s²
Therefore
Ug=mgh
Ug=1.3 × 1/6371 ×1609
Ug=0.328J
Total energy = 0.328+350.84
Ug=351.17J
Answer:
Frequency and wavelength are inversely proportional to each other. The wave with the greatest frequency has the shortest wavelength. Twice the frequency means one-half the wavelength. For this reason, the wavelength ratio is the inverse of the frequency ratio.