Question

A person pushes with a force of 10.0 N on a stick pin to try to push it into a bulletin board. If the tip of the needle is a circle with a radius of 0.12 mm, then what is the average pressure on the board at the tip of the pin 2.120E + 08 Pa 1.685E + 08 Pa 2.495E + 08 Pa 2.526E + 08 Pa 1.931E + 08 Pa 2.236E + 08 Pa An object has a volume of 0.25 m^3 and weighs 3000N. What will be its apparent weight when submerged in water 550.0 N 432.3 N 624.9 N 533.3 N 532.8 N 662.1 N A plastic block of dimensions 2.5 cm x 3.8 cm x 4.0 cm has a mass of 28.0 g. What is the density of the block If placed into a cup of water, will the btock float or sink 0.5955 g/cm^3 0.7502 g/cm^3 0.7368 g/cm^3 0.7598 g/cm^3 0.6361 g/cm^3 0.6541 g/cm^3 float or sink Float Sink A concrete block of dimensions 1.00 m * 2.50 m * 2.75 m has what weight in Newtons Use 2400 kg/m^3 as the density of concrete. 1.433E + 05 N 1.440E + 05 N 1.909E + 05 N 1.682E + 05 N 1.617E + 05 N 1.773E + 05 N A 13000 N vehicle is to be lifted by a 25 cm diameter hydraulic piston. What force needs to be applied to a 3.5 cm diameter piston to accomplish this 226.1 N 254.7 N 279.4 N 254.8 N 309.7 N 311.8 N

Answer 1

Here ,

1)

Pressure = force/area

Pressure = 10/(pi * (0.12 *10^-3)^2)

Pressure = 2.210 E+8 Pa

the pressure is A) 2.210 E+8 Pa

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2)

Here , for the apprent weight

apprent weight = Weight of object - weight of water displaced

apprent weight = 3000 - 0.25 * 1000 * 9.8

apprent weight = 550 N

the apprent weight is a) 550 N

3)

density = mass/volume

density = 28/(2.5 * 3.8 * 4) g/cm^3

density = 0.7368 g/cm^3

the density is c) 0.7368 g/cm^3

4.

as the density of plastic block is less than the density of water

it will a) Float