Answer:
(a) The angle of projection is 63 degree.
(b) The velocity of projection is 24.5 m/s.
Explanation:
Height, h = 1 m
horizontal distance, d = 50 m
time, t = 4.5 s
Let the initial velocity is u and the angle is A.
(a) Horizontal distance = horizontal velocity x time
50 = u cos A x 4.5
u cos A = 11.1 .....(1)
Use second equation of motion in vertical direction

Divide (2) by (1)
tan A = 1.97
A = 63 degree
(b) Substitute the value of A in equation (2)
u x sin 63 = 21.8
u = 24.5 m/s
An exothermic reaction is a chemical reaction that releases heat. It gives net energy to its surroundings. That is, the energy needed to initiate the reaction is less than the energy released. ... Δ H = (energy used in forming product bonds) − (energy released in breaking reactant bonds)
Answer:
The distance covered by puck A before collision is 
Explanation:
From the question we are told that
The label on the two hockey pucks is A and B
The distance between the two hockey pucks is D 18.0 m
The speed of puck A is 
The speed of puck B is 
The distance covered by puck A is mathematically represented as

=> 
The distance covered by puck B is mathematically represented as

=> 
Since the time take before collision is the same

substituting values

=> 
=> 
Explanation:
Hey, there!
Answer: It sinks more.
We know that the water of sea is salty in nature which increases the density of water in sea and donot let's ship sink but in condition of river water it doesn't have any effects of salty water as it doesn't contain salty water due to which it's density is no more than the densityof ship which let's it sink more than sea water.
<em><u>Hope</u></em><em><u> </u></em><em><u>it helps</u></em><em><u>.</u></em><em><u>.</u></em><em><u>.</u></em>
Newton's second law of motion states the following:

In which

is the force,

is the mass, and

is the acceleration of the object.
So, the answer is B.