Initially the box is at rest. Person pushes box gently, but gradually increases the force so the force exerted on the box varies in time as F = (8.6 N/s)t. After 3 s they stop pushing the box. Force is always exerted in the same direction.
How far have they pushed the box in 3 s (answer in m)?
What is the velocity of the box after 3s (answer in m/s)?
2006-09-27 08:23:42 · 5 answers · asked by Dee 4 in Science & Mathematics ➔ Physics
Keep working these & I don't think these 2 answer are correct. Thought once I got these I could also figure these:
What is the average velocity of the box between 0 s and t? answer in m/s
What is the average force that the man exets on the box while he is pushing it? answer in N
If you know any of the 4 parts to this question, please help!
2006-09-30 12:56:31 · update #1
0.043m/s
0.13m
2006-09-27 08:35:20 · answer #1 · answered by honeyrlr 3 · 0⤊ 1⤋
First off, force is measured in Newtons. If the F=8.6n and the M=22 kg, you can find the a........F=MA.........So A comes out to be .39ms2.
To find the speed after 3s, you just multiplt .39 x 3, because V=AT
To find the dist you use d=1/2 at2. You know A=.39 and you know t=3s, so there you have it.
2006-10-05 08:28:57 · answer #2 · answered by jay k 1 · 0⤊ 0⤋
Energy conservation:
0.5*m*V^2=F*S,
where m is mass & V is velocity of box; F is force exerted and S is distance pushed. Hence,
S=0.5*m*V^2/F
S=0.5*m*V^2/(8.6*t)
where t is time elapsed. Thus,
S= 0.5*22*V^2/(8.6*3)
S=0.426*V^2-------(1)
S=V*t=3*V-----------------(2)
Equating (1) and (2), we get:
V=7.04 m/s
S=3*7.04
S=21.1 meters
Therefore, they have pushed the box 21.1 meters in 3 seconds and the velocity after 3 seconds is 7.04 m/s.
2006-09-27 23:52:56 · answer #3 · answered by mekaban 3 · 0⤊ 0⤋
F=Ma
a=F/M=8.6/22=.3909m/s^2
v=integral(ADT=.195T^2
a) v(3)=.195*9=1.75m/s
d=integral(vdt)=.06515t^3
b) d(3)=.175m
c) v(av)=d/t=1.75m/3s=.586m/s
w=integral(Fd(distance)
F=8.6N/s*t
d=.06515t^3
t=2.485d^(1/3)
w=integral(2.485d d(d))
w=3.93 J
F(av)=work/distance=3.93/1.75=2.246 N
2006-10-04 08:11:30 · answer #4 · answered by yupchagee 7 · 0⤊ 0⤋
as far as they pushed it.
do you even know this answer? if so, why do you ask?!?!?
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2006-10-03 15:01:50 · answer #5 · answered by 234retgf 3 · 0⤊ 0⤋