Answer:
The time taken will be 0.553 seconds.
Explanation:
We should start off by finding the force exerted by the rope on the 3kg weight in this case.
Weight of 5kg mass = 5 * 9.81 = 49.05 N
Weight of 3kg mass = 3 * 9.81 = 29.43 N
The force acting upward on the 3kg mass will equal the weight of the 5kg mass. Thus the resultant force acting on the 3kg mass is:
Total force = 49.05 - 29.43 = 19.62 N (upwards)
We can now find the acceleration:
F = m * a
19.62 = 3 * a
a = 6.54 m/s^2
We now use the following equation of motion to get the time taken to travel 1 meter:
t = 0.553 seconds
The statement "<span>Forces always act alone" is false. Force do not always act alone. It is always accompanied by another force that is always opposite to it. </span>
The question is incomplete, the complete question is;
A body initially at a all 100 degree centigarde cools to 60 degree centigarde in 5 minutes and to 40 degree centigarde in 10 minutes . What is the temperature of surrounding? What will be the temperature in 15 minutes?
Answer:
See explanation
Explanation:
From Newton's law of cooling;
θ1 - θ2/t = K(θ1 + θ2/2 - θo]
Where;
θ1 and θ2 are initial and final temperatures
θo is the temperature of the surroundings
K is the constant
t is the time taken
Hence;
100 - 60/5 = K(100 + 60/2 - θo)
100 - 40/10 = K(100 + 40/2 - θo)
8= (80 - θo)K -----(1)
6= (70 - θo)K -----(2)
Diving (1) by (2)
8/6 = (80 - θo)/(70 - θo)
8(70 - θo) = 6(80 - θo)
560 - 8θo = 480 - θo
560 - 480 = -θo + 8θo
80 = 7θo
θo = 11.4°
Again from Newton's law of cooling;
θ = θo + Ce^-kt
Where;
t= 0, θ = 60° and θo = 11.4°
60 = 11.4 + C e^-K(0)
60 - 11.4 = C
C= 48.6°
To obtain K
40 = 11.4 + 48.6e^-10k
40 -11.4 = 48.6e^-10k
28.6/48.6 = e^-10k
0.5585 = e^-10k
-10k = ln0.5585
k= ln0.5585/-10
K= 0.0583
Hence, the temperature in 15 minutes;
θ= 11.4 + 48.6e^(-0.0583 × 15)
θ= 31.7°
Answer:
9080 N
Explanation:
Consider the two motions of the ball.
In the downward motion, initial velocity, <em>u</em>, is 0 (because it falls from rest) and the distance is 28.7 m. Using the equation of motion and using <em>g</em> as 9.8 m/s²,
<em>v² = u² + 2as</em>
<em>v² = </em>0² + 2 × 9.8 × 28.7<em> </em>= 562.52
<em>v = </em>19.7 m/s
<em />
For the downward motion, the initial velocity is unknown, the final velocity is 0 and initial velocity is desired. <em>g</em> is negative because the motion is upwars.
<em>0² = v² - </em>2 × 9.8 × 19.8
<em>v² = </em>388.08
<em>v = </em>10.7 m/s
The change in momentum = 0.502(10.7 -(23.7)) = 21.7868 kgm/s
The impulse = change in monetum
Ft = 21.7868 kgm/s
But t = 2.4 ms
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cant really answer here with text but at the top of the slide it should br positives and towards the bottom its negative.
This is because you go faster at the top of the slide than the bottom and when your at the bottom you slow down
