Answer:
Rotational inertia of the object is, 
Explanation:
Given that,
Mass of the object, m = 20 kg
Torsion constant of the wire, K = 0.85 N-m
Number of cycles, n = 69
Time, t = 66 s
To find,
The rotational inertia of the object.
Solution,
There exists a relationship between the moment of inertia, time period and the torsion constant of the spring is given by :

Here I is the moment of inertia
T is the time period, and it is equal to the number of cycles per unit time



So, the rotational inertia of the object is
.
Explanation:
1) the diagonal force times the sine of the angle it makes will give you the vertical component or y component . use this to get the vertical components of all the diagonal forces . add all the vertical components as well as the vertical forces together
2) the diagonal force times the cosine of the angle it makes gives the horizontal component or x component. do this to get the x component of all the diagonal forces.
add all the x components as well as the horizontal forces together to get the final x component
3)using the triangle of vectors, the resultant force is calculated
sum of y component = 3.2N
sum of x component= 5.7N
resultant force = 6.5N
X ray is one of the electromagnetic waves.
As per Clark Maxwell's electromagnetic theory, all the electromagnetic waves move with the velocity of light i.e c= 3×10^8 m/s
In case of electromagnetic waves,the electric field and magnetic field are perpendicular to each other as well as perpendicular to the direction of propagation.The electromagnetic waves exhibit the property of polarisation. Hence they are transverse in nature.
Hence the best statements about X- ray will be-
1- X -rays are electromagnetic waves
2-X-rays are transverse transverse waves
3- X- rays travel at the speed of light.
Answer:
D) Heavier objects need a greater force to accelerate according to F=ma.
Explanation:
The force of gravity acting on an object is equal to:
F = mg
where m is the mass of the object and g is the acceleration due to gravity. According to the formula, heavier objects (objects with greater mass, m) have a larger force of gravity acting on them.
However, the acceleration of an object towards the ground is given by:

therefore, we see that if the object is heavier (larger mass, m), the force of gravity (F) must also be larger in order to have the same acceleration a.