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# A total mass of 80kg rides an elevator. Determine the force exerted on the floor of the elevator when it is accelerating upward at 5.0 m/s2.?

### 6 Answers

- MyRankLv 61 month ago
Given,

Mass (m) = 80 kg

Acceleration (a) = 5 m/sec²

Force (F) = ?

Here, force of body accelerating against gravitational field. So,

F_Net = m(g+a) = 80(9.81 + 5)

= 1184.8 ≈ 1185 N.

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- NCSLv 76 months ago
For a body accelerating AGAINST a gravitational field (as in this case),

net F = m*(g+a)

so

F = 80kg * (9.8+5.0)m/s² = 1180 N ≈ 1200 N

since the answer SHOULD be to 2 significant digits.

Note the for a body accelerating WITH a gravitational field (such as an elevator beginning its descent),

F = m*(g - a)

Hope this helps!

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- electron1Lv 76 months ago
The force on the floor is the sum of the weight of the elevator and the force that causes it to accelerate.

Weight = 80 * 9.8 = 784 N

Force = 80 * 5 = 400 N

Total force = 784 + 400 = 1,184 N

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- daniel gLv 76 months ago
Enough to turn people to shoo goo on the floor.

Oh my bad, thought we were talking megaparsecs here.

That is like 120.73 Kg mass weight.

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- JOHNLv 76 months ago
Forces on 60kg mass:

R (reaction of elevator floor, up direction)

W (weight of mass, down direction).

Newton's 2nd law:

R - W = R - 80g = 80(5.0)

R = 80 x 9.8 + 80 x 5.0 = 1184N.

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