For the lovers of Physics

For the lovers of Physics

simplemind said:
equation of motion of man 2T+R-60g=60x2 ........(a)
equation of motion cage 2T-R-40g=40x2 ..........(b)
add a to b to eliminate R 4T-100g=200
ie 4T=1200
T=300N(tension force)
substitute T equation (b) 600-R-400=200
200-R=200
Reaction force suprisingly enough equals 0 ????? Is it 😳
Click to expand...


You are right in the case of T=300N, but wrong in the reaction R, which is 120N. Good try mkuu.
 
Mokaze said:
You are right in the case of T=300N, but wrong in the reaction R, which is 120N. Good try mkuu.
Click to expand...
Computational error equation (b), should read 600-R-400=40X2=80 not 200.
hence R=120.
Gday.
 
Mokaze said:
The sensible depth "d" of the well is 28.64 metres . Taking c=343m/s.
Click to expand...

GRAPHICAL METHOD USING EXCEL

t=2.5 sec
d=g/2*t1^2
d=ct2
t2=g/2c*t1^2
t=t1+t2
2.5=t1+0.0142t1^2
f(t)= 0.0143t1^2+t1-2.5=0 (quadratic equation)


tf(t)
2.4000-0.01936
2.4010-0.01829279
2.4020-0.01722554
2.4030-0.01615827
2.4040-0.01509098
2.4050-0.01402365
2.4060-0.0129563
2.4070-0.01188891
2.4080-0.0108215
2.4090-0.00975407
2.4100-0.0086866
2.4110-0.00761911
2.4120-0.00655158
2.4130-0.00548403
2.4140-0.00441646
2.4150-0.00334885
2.4160-0.00228122
2.4170-0.00121355
2.4180-0.00014586
2.41900.00092185
2.42000.0019896
2.42100.00305737
2.42200.00412518
2.42300.00519301
2.42400.00626086
2.42500.00732875

1618962543940.png



Now it is evident the curve crosses the t-axis t = 2.41 and 2.42 approximately ≈ 2.416
d=g/2*t1^2
Having the value real value of t, d = 9.81x (2.416)^2/2

d≈ 28.63m
 
Teknologist said:
Tuendelee na Physics........
Ifuatayo ni kati ya maswali ya interview kujiunga na TISS...........😁


A detective is interested in finding the depth of a well where he believes a criminal has
hidden a gun. The detective drops a stone into the well, and measures the time before a
splash is heard. The total time t consists of the time it takes for the stone to hit the water
t1 and the time it takes for the sound to travel from the surface of the water to the
detectives’ ear t2. If g is acceleration due to gravity, d the depth of the well and c the
speed of sound in air then we can write:
View attachment 1755100
By rearranging the formulae, find a sensible solution for the depth of the well given that
the detective counts 2.5 seconds before hearing the splash.
Take g as 9.81 m/ s2 and c as the speed of sound in air at atmospheric pressure and 20°C.
Click to expand...

Teknologist said:
Tuendelee na Physics........
Ifuatayo ni kati ya maswali ya interview kujiunga na TISS...........😁


A detective is interested in finding the depth of a well where he believes a criminal has
hidden a gun. The detective drops a stone into the well, and measures the time before a
splash is heard. The total time t consists of the time it takes for the stone to hit the water
t1 and the time it takes for the sound to travel from the surface of the water to the
detectives’ ear t2. If g is acceleration due to gravity, d the depth of the well and c the
speed of sound in air then we can write:
View attachment 1755100
By rearranging the formulae, find a sensible solution for the depth of the well given that
the detective counts 2.5 seconds before hearing the splash.
Take g as 9.81 m/ s2 and c as the speed of sound in air at atmospheric pressure and 20°C.
Click to expand...
(a) 2d=4.9xt1^2+340Xt2.
(b) t2=2.5-t1
subst. t2 in
Teknologist said:
GRAPHICAL METHOD USING EXCEL

t=2.5 sec
d=g/2*t1^2
d=ct2
t2=g/2c*t1^2
t=t1+t2
2.5=t1+0.0142t1^2
f(t)= 0.0143t1^2+t1-2.5=0 (quadratic equation)


tf(t)
2.4000-0.01936
2.4010-0.01829279
2.4020-0.01722554
2.4030-0.01615827
2.4040-0.01509098
2.4050-0.01402365
2.4060-0.0129563
2.4070-0.01188891
2.4080-0.0108215
2.4090-0.00975407
2.4100-0.0086866
2.4110-0.00761911
2.4120-0.00655158
2.4130-0.00548403
2.4140-0.00441646
2.4150-0.00334885
2.4160-0.00228122
2.4170-0.00121355
2.4180-0.00014586
2.41900.00092185
2.42000.0019896
2.42100.00305737
2.42200.00412518
2.42300.00519301
2.42400.00626086
2.42500.00732875
​


View attachment 1758815


Now it is evident the curve crosses the t-axis t = 2.41 and 2.42 approximately ≈ 2.416
d=g/2*t1^2
Having the value real value of t, d = 9.81x (2.416)^2/2

d≈ 28.63m
Click to expand...
A neat ,exact and quick solution to quadratic equation is provided by quadratic formula: given ax²+bx+c=0 then x=(-b±√(b²-4ac))/(2a). Another possibility is use of numerical method(an overkill for simple quadratic).
 
Hello the Physics lovers, here is another simple puzzle to remind yourself of your mechanics prowess.😇


A ring shaped elastic rubber having Mass "M" is released to slide frictionlessly outside a round conical shape cylinder to a point where it stop outside the cylinder as shown in the diagram.

Qn, Find tension force "T" in the rubber at the stoppage point, given the conical apex angle theta.

Screenshot_20210430-192542.png
 
Mokaze said:
Hello the Physics lovers, here is another simple puzzle to remind yourself of your mechanics prowess.😇


A ring shaped elastic rubber having Mass "M" is released to slide frictionlessly outside a round conical shape cylinder to a point where it stop outside the cylinder as shown in the diagram.

Qn, Find tension force "T" in the rubber at the stoppage point, given the conical apex angle theta.

View attachment 1769336
Click to expand...
Haya ndio mambo yalinifanya nijibidiishe kukariri definitions tu😅
 
IMG_20220511_071707_612.jpg



For the physics lovers; in the above figure, the red dots are riverts which hold together the members 1,2,3 and 4 and allow the member to move freely while the dots being axes, the blue line is a string tied from the above to the below point of the figure, given the members 1,2,3and 4 each having mass M and the angle between members 1and 2 being theta, then What is the tension T existing in the blue string R ??

NB: [Neglecting the mass of the string, the whole figure is being hanged somewhere above with a rope]
 
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