a) What is the weight of a 5.53 kg backpack?
(b) What is the acceleration of the backpack if a net force of 13.7 N is applied?
2006-09-22 10:05:23 · 5 answers · asked by P 1 in Science & Mathematics ➔ Mathematics
Mass is a measurement of the amount of matter something contains, while weight is the measurement of the pull of gravity on an object.
On Earth, we typically refer to the weight of something using the mass (e.g. 5.53 kg). But the "weight" of that same backpack on the moon will be approximately 1/6 that "weight"... so the answer depends on where you want to know the weight.
a) Let's assume that you want the "weight" of the backback on Earth and by "weight" you really mean "force of gravity"
The force of gravity on that 5.53 kg backpack (assuming Earth's gravitation of 9.8 m/s/s) can be computed using Newton's law:
F = ma
F = 5.53 kg * 9.8 m/s²
F = 55.2 Newtons
b) Again you would use the formula F = ma, but in the opposite direction. The mass is 5.53 kg, the force is 13.7 Newtons, so the acceration will be:
F = ma
13.7 = 5.53 * a
a = 13.7 Newtons / 5.53 kg
a = 2.47739602 m/s/s
So the acceleration of the backpack is approximately 2.5 meters/sec²
2006-09-22 10:14:58 · answer #1 · answered by Puzzling 7 · 0⤊ 0⤋
Didn't phrase that too well now didya?
I assume the question is actually asking for the gravitational force experienced by the backpack, which would actually be 5.53 x 9.81 m.s^-2 (9.81 being the acceleration due to gravity).
Gotta love high school physics.
Right, the next question, F = m.a. You have a mass, and you have a force, so it shouldn't be too hard to get an acceleration.
2006-09-22 17:15:14 · answer #2 · answered by Kiwi Chicken 2 · 0⤊ 0⤋
to the previous answer kg is not weight it is mass. the units for weight is newtons
now a) if you are looking to the weight (weight is a force) in N which I am assuming given b, it is the mass times gravity, so 5.53kg X 9.8m/s^2 (or 10m?s^2 depending on the book you are using) = 54.194N or 55.3 N(gravity is 10).
now working backwards
force = mass X acceleration
therefore acceleration = force/mass
13.7N/5.53kg = 2.48m/s^2
2006-09-22 17:22:34 · answer #3 · answered by rikki71685 1 · 0⤊ 0⤋
Looking forward to seeing expert answers here, 'cos I always thought that a 5.53kg anything weighed 5.53kg.
2006-09-22 17:10:31 · answer #4 · answered by migdalski 7 · 0⤊ 0⤋
a) the weight is 5.53kg(9.8m/s^2)=54.2N
b)acceleration = 13.7N/5.53kg= 2.5m/s^2
2006-09-22 17:17:25 · answer #5 · answered by Greg G 5 · 0⤊ 0⤋