Answer:
Explanation:
The horizontal distance traveled by the projectile is given by the formula

The formula for the time of flight is given by

Case I: when the launch angle is 30°
So, 

Horizontal velocity = u Cos 30 = 0.866 u

Case II: when the launch angle is 60°


Horizontal velocity = u Cos 60 = 0.5 u

By observing the case I and case II, we conclude that
R1 = R2
Horizontal velocity 1 > Horizontal velocity 2
T1 < T2
Escape velocity is the velocity an object needs to escape the gravitational influence of a body if it is in free fall, i.e. no force other than gravity acts on it. Your rocket is not in free fall since it is using its thruster to maintain a constant velocity so the notion of "escape velocity" does not apply to it.
Answer:
The velocity is
Explanation:
From the question we are told that
The mass of the ball is 
The radius is 
The force is 
The speed of the ball is 
Generally the kinetic energy at the top of the circle is mathematically represented as

=>
=>
Generally the work done by the force applied on the ball from the top to the bottom is mathematically represented as

Here d is the length of a semi - circular arc which is mathematically represented as

So


Generally the kinetic energy at the bottom is mathematically represented as

=> 
=> 
From the law of energy conservation

=> 
=>
Answer:
An opaque object with many closely spaced slits
Explanation:
Diffraction grating is an opaque object which will have many close slits on it
Each slit will allow the light wave pass through it which incident on it.
So here each slit will behave like a secondary source which will transmit the light and the superposition of light is then observed on the screen
These large number of slits on the object is combined known as diffraction grating.
By the superposition of waves due to grating we will have pattern of maximum and minimum intensity on the screen and this intensity if highest at the mid point of screen and then decreases as we move away
The statement ‘A tertiary source is the most desirable source for a
researcher to use’ is false. It should be that your source is primary because
it is more reliable and is related to the research you have been working on.