A) calculate the acceleration if you push with a 20-N horizontal force on a 2-kg block on a horizontal friction-free air table?
B) what acceleration occurs if the friction force is 4N?
please explain the concept.
2006-12-05 11:16:15 · 8 answers · asked by smile 3 in Science & Mathematics ➔ Physics
20 feet per second dont you know how to answer these questions????
2006-12-05 11:18:41 · answer #1 · answered by Anonymous · 0⤊ 4⤋
You need to look at Newtons laws of motion:
1. Every body will remain at rest, or in a uniform state of motion unless acted upon by a force.
2. When a force acts upon a body, it imparts an acceleration proportional to the force and inversely proportional to the mass of the body and in the direction of the force.
3. Every action has an equal and opposite reaction.
The answer to question A uses Newtons second law, stated by the formula F = ma, hence acceleration = force/mass:
acceleration = 20N / 2kg = 10 m per sec per sec.
The answer to B uses laws 2 & 3. The 4N of friction cancels out some of the pushing force so it can be deducted, i.e. 20N - 4N = 16N.
Use same formula as in A, but now the force is 16N:
acceleration = 16N / 2kg = 8m per sec per sec
Some of the previous answers were correct, but I thought a bit of Newton might help you to visualise what is going on. It took me a long time before I became fluent in Newtons laws, so I appreciate what you are going through.
2006-12-05 11:50:51 · answer #2 · answered by Billy 2 · 2⤊ 0⤋
Force = mass x acceleration
A) 20 divided by 2 = 10 m/s^2
B) 4N divided by 2 = 2 m/s^2
2006-12-05 11:19:49 · answer #3 · answered by Atilt 1 · 1⤊ 1⤋
the conventional rigidity = 2 hundred(9.80 one) = 1962 N The friction rigidity = (0.20)(1962) = 392 N the internet utilized rigidity = 685 - 392 = 293 N The acceleration of field = 293/2 hundred = a million.40 six m/s² ANS
2016-11-23 18:58:45 · answer #4 · answered by Anonymous · 0⤊ 0⤋
I reckon A, 10 m/s/s
and B, 8 m/s/s
the co-efficient of friction is a force working against the object at the point of calculation.
2006-12-05 11:27:24 · answer #5 · answered by jimbo_thedude 4 · 1⤊ 0⤋
A) F=ma => 20=2a => a=10 m/s2
B) F-f=ma => 20-4=2a => 16=2a => a=8 m/s2
2006-12-06 13:49:51 · answer #6 · answered by Kemmy 6 · 0⤊ 0⤋
net force =20-4=16N. thus acceleration is 16/mass or 16/2=8m/s2
2006-12-05 11:20:24 · answer #7 · answered by Sanjay C 2 · 2⤊ 0⤋
a) F=ma
20N=(2kg)a
a= 10m/s^2
b) 20-4= 16N
F=ma
16N=(2kg) a
a= 8m/s^2
2006-12-05 11:20:46 · answer #8 · answered by 7 · 2⤊ 0⤋