4. A section of granite floor is capable of sustaining 500 P.A. of pressure. If a 2000kg
rectangular weight of dimensions 10m X 4m is resting on it, will the granite floor break? (Hint, use F=MA, then P=F/A)
7. For obvious reasons, men on stilts are not allowed in rooms with styrofoam floors. If
Styrofoam floors collapse under pressures above 24,000 ppi and a stilt man accidentally wanders
in wearing stilts with a radius of .05 meters and weighing 50 kg, would he Styrofoam floor be
pierced? (Area of a Circle=2 pi r^2)
11. Somehow, a glitch in time occurs and your car is transplanted onto a possum. If your car is
4000 kg, a possum is crushed at 15,000 ppi, and at any given time only .4 sqr. meters of each tire
is touching the ground, will the possum get crushed under one of your tires?
12. Imagine that you find a pin so small that it is virtually invisible. If the tip of the pin is only
.000001 sqr. meters, how hard would you have to push to penetrate a metal from mars that resist
a pressure of 500,000,000 ppi? Is this possible for a mere mortal?
17. Your super-light travel umbrella has a mass of 200 g. If you are
balancing its tip, approx. 3 cm2, on your finger, what pressure is being put on your finger? What
if it’s raining, and the rain on the umbrella adds a force of 2 N? (F=MA, for the weight of the umbrella, then P=F/A)
4. ma=f
(2000kg)(-9.8)=F
F=-19,600 N
P=F/A
=19,600 N / 40m2
=490 P.A.
500 P.A. > 490 P.A.
No, the floor will not break.
7. A = (3.14)(r^2)(2)
A = .0157 m^2
P = F/A
P = (50)(9.8)/(.0157) = 31,210
There goes the floor.
11. P = F/A
P = (4000)(9.8)/(.4)(4)
P = 24,500
24,500 > 15,000 so the possum is crushed!!
12. P = F/A
P = (F)/(.000001) = 500,000,000
F = 500 ppi
It’s easy
rectangular weight of dimensions 10m X 4m is resting on it, will the granite floor break? (Hint, use F=MA, then P=F/A)
7. For obvious reasons, men on stilts are not allowed in rooms with styrofoam floors. If
Styrofoam floors collapse under pressures above 24,000 ppi and a stilt man accidentally wanders
in wearing stilts with a radius of .05 meters and weighing 50 kg, would he Styrofoam floor be
pierced? (Area of a Circle=2 pi r^2)
11. Somehow, a glitch in time occurs and your car is transplanted onto a possum. If your car is
4000 kg, a possum is crushed at 15,000 ppi, and at any given time only .4 sqr. meters of each tire
is touching the ground, will the possum get crushed under one of your tires?
12. Imagine that you find a pin so small that it is virtually invisible. If the tip of the pin is only
.000001 sqr. meters, how hard would you have to push to penetrate a metal from mars that resist
a pressure of 500,000,000 ppi? Is this possible for a mere mortal?
17. Your super-light travel umbrella has a mass of 200 g. If you are
balancing its tip, approx. 3 cm2, on your finger, what pressure is being put on your finger? What
if it’s raining, and the rain on the umbrella adds a force of 2 N? (F=MA, for the weight of the umbrella, then P=F/A)
4. ma=f
(2000kg)(-9.8)=F
F=-19,600 N
P=F/A
=19,600 N / 40m2
=490 P.A.
500 P.A. > 490 P.A.
No, the floor will not break.
7. A = (3.14)(r^2)(2)
A = .0157 m^2
P = F/A
P = (50)(9.8)/(.0157) = 31,210
There goes the floor.
11. P = F/A
P = (4000)(9.8)/(.4)(4)
P = 24,500
24,500 > 15,000 so the possum is crushed!!
12. P = F/A
P = (F)/(.000001) = 500,000,000
F = 500 ppi
It’s easy
17. The Answer will be posted later.