2.1) (i) W = mg downwards
(ii) N = R = Normal Reaction from the ground upwards
(iii) Fe = Force of engine towards the right
(iv) f = friction towards the left
(v) ma = Constant acceleration towards right.
2.2.1)
v = 25 m/s
u = 0 m/s
∆v = v - u = (25 - 0) m/s = 25 m/s
x = X
∆t = 50 s

a = 0.5 m/s².
2.2.2)
F = ma = 900 kg × 0.5 m/s² = 450 N.
2.2.3)


2.3)
Fe = f + ma
Fe - f = ma
For velocity to be constant,
a should be 0, or, a = 0,
Fe = f = 270 N
2.4.1)
v = 0
u = 25 m/s
a = -0.5 m/s²
v = u + at
t = -u/a = -(25)/(-0.5) = 50 s.
2.4.2)
x = -625/(2×(-0.5)) = 625 m.
Answer:
75.5g
Explanation:
From the ionic equation, we can write

next we find the number of charge
Note Q=it
for i=8.5A, t=3.75 to secs 3.75*60*60=13500secs
hence

Since one faraday represent one mole of electron which equal 96500C
Hence the number of mole produced by 114750C is
114750/96500=1.2mol
The mass of copper produced is

Hence the amount of copper produced is 75.5g
<span>Brass is an <u>alloy</u>. An alloy
is a mixture of elements to form a unique material. Brass is a mixture of copper
and zinc and the percentage of each element depends on the desired material. It
has a higher malleability than bronze or zinc. Meaning that it can be bend
easily into it desired form.</span>
Answer:
B
Explanation:
You always want to test as many samples as possible
In order to solve the problem, it is necessary to apply the concepts related to the conservation of momentum, especially when there is an impact or the throwing of an object.
The equation that defines the linear moment is given by

where,
m=Total mass
Mass of Object
Velocity before throwing
Final Velocity
Velocity of Object
Our values are:

Solving to find the final speed, after throwing the object we have

We have three objects. For each object a launch is made so the final mass (denominator) will begin to be subtracted successively. In addition, during each new launch the initial speed will be given for each object thrown again.
That way during each section the equations should be modified depending on the previous one, let's start:
A) 



B) 



C) 



Therefore the final velocity of astronaut is 3.63m/s