Help ! Physics?

Question

Calculate the apparent weight of Paul, whose mass is 80kg, in a life that is..
a. At rest.
b. Accelerating upwards at 2.2ms-1
d. slowing upwards at 2.2ms-1
This one would be based on W=mg

Answer 1

W = mg

Assuming a gravitational field 9.8 m/s^2 downwards (ie Earth gravity)

(a) At rest
W = 784N

(b) Accelerating upwards at 2.2m/s^2
W = 80 x 7.6kgm/s^2
= 608N

(d) (What happened to (c) ?)
umm - what do you mean by slowing upwards?

If you mean accelerating downwards at 2.2m/s^2
W = 80 x 12 kgm/s^2
= 960N

Answer 2

I presume that by life you actually mean lift. Perhaps you misspelled ‘t’!

At rest: W =mg = 80kg x 9.8m/s-1 = 784N
Accelerating upwards at 2.2m/s-1: W = m (g + a) = 80kg (9.8m/s-1 + 2.2m/s-1) = 80kg x 12m/s-1 = 960N
Accelerating at –2.2m/s-1: W = m (g – a) = 80kg (9.8m/s-1 – 2.2m/s-1) = 80kg x 7.6m/s-1 = 60.8N

If you want all of this in pounds simply multiply the weight in Newtons by 0.224.

Answer 3

Rule of thumb.

Lift moving up--- Add
Lift moving down-- subtract ( If a lift is falling down, you experience weightlessness)

So
a> weight = mg

b> Weight = m * g' = 80 (9.8 + 2.2)

c> rest is same as moving at uniform velocity, no unbalance forces in action .
so weight =mg. as in part a

If lift came down with accelaration, you'd have to subtract that accelaration from 9.8

Answer 4

i think it is lift not "life".
well that is R = m(g + f )
R = normal reaction on the man which is the apparent weight
g = acceleration due gravity
f = acc. of lift
m = mass of man
u can solve ur problem on this formula thanx

Answer 5

80








































80kg regardless