Answer:
150 million kilometres
Explanation:
The astronomical unit (symbol: au, or AU or AU) is a unit of length, roughly the distance from Earth to the Sun and equal to 150 million kilometres (93 million miles) or 8.3 light minutes.
Answer:
Time taken, 
Explanation:
It is given that, a small metal ball is suspended from the ceiling by a thread of negligible mass. The ball is then set in motion in a horizontal circle so that the thread’s trajectory describes a cone as shown in attached figure.
From the figure,
The sum of forces in y direction is :


Sum of forces in x direction,

.............(1)
Also, 
Equation (1) becomes :

...............(2)
Let t is the time taken for the ball to rotate once around the axis. It is given by :

Put the value of T from equation (2) to the above expression:


On solving above equation :

Hence, this is the required solution.
Answer:
False
Explanation:
The steel ball and the wooden ball do not have the same force acting on them because their masses are different. But, they have the same acceleration which is the acceleration due to gravity g = 9.8 m/s².
Using the equation of motion under freefall, s = ut +1/2gt². Since u = 0,
s = 1/2gt² ⇒ t = √(2s/g)
Since. s = height is the same for both objects, they land at the same time neglecting air resistance.
Answer:
-0.045 N, they will attract each other
Explanation:
The strength of the electrostatic force exerted on a charge is given by

where
q is the magnitude of the charge
E is the electric field magnitude
In this problem,

(negative because inward)
So the strength of the electrostatic force is

Moreover, the charge will be attracted towards the source of the electric field. In fact, the text says that the electric field points inward: this means that the source charge is negative, so the other charge (which is positive) is attracted towards it.