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i posted this earlier but got a confusing answer so pls help as best as u can asap!

True or False 1. If a 40 kg person is accelerating at 10 m/s2, then the magnitude of the force acting on him or her is 400 N.

(1 point) TRUE FALSE Multiple Choice 2. How much force is needed to make a 60 kg object accelerate at a rate of 2.0 m/s2? (1 point)

62 N 62 kg 120 N 120 kg 3. What is the acceleration of a 30 kg object when 180 N of force is applied to it? (1 point)

6.0 m/s^2 60 m/s^2 210 m/s^2 5,400 m/s^2 4. Which of the following equations shows how you would solve for mass if you knew the force acting on an object and the acceleration of an object?

(1 point) m = f/a m = fa m = a/f m = f − a soooooo need help!!! dunno what they are talking about! cant guess!

pls help asap!!!!! thanx in advance

Verified Answer :

jtvatsim

Whoa, whoa... settle down there. We'll sort you out.

All of your questions in life can be solved using one simple formula:
F = ma

In english, this is 
Force = (mass)(acceleration)
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[1] Let's identify the mass. Kg (kilograms) is a mass unit, so we know that
m = 40.
The acceleration is a = 10 m/s^2.

The question is, is the force 400 N? Let's check against the formula:
F = ma
F = (40 kg)(10 m/s^2)
F = 400 kgm/s^2
F = 400 N

Yes. The answer is true.
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[2] The mass is m = 60 kg. The acceleration is a = 2.0 m/s^2. The force is 
F = ma
F = (60 kg)(2.0 m/s^2)
F = 120 kgm/s^2
F = 120 N.

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[3] The mass is m = 30 kg. The force is 180 N. Ah, this is a little different, now we don't know the acceleration. But the same formula works:
F = ma
180 N = (30 kg)a
180 N / 30 kg  = a
6.0 m/s^2 = a

The acceleration is 6.0 m/s^2.
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[4] This is a hypothetical question. Suppose we know the force F and the acceleration a, but we don't know the mass m. I'll put m in a box [m] so that we remember that this is the one we don't know. The same formula works:
F = ma
F = [m]a   <--- m is the one we don't know
F / a = [m]

In reality, we would have numbers for F and a, but since we are just pretending we are done!

m = F/a is the formula.
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See? Not too bad. :)


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