Question 1

How large a force is necessary to stretch a 1-mm-diameter steel wire (Y = 2.0 × 10¹¹ N/m²)by 8.0%? A) 19.0 × 10³ N B) 12.6 × 10³ N C) 12.3 × 10³ N D) 25.1 × 10⁴ N E) 12.6 × 10⁴ N

Accepted Answer

The force required to stretch a spring or wire is given by the equation:
F = Y(ΔL/L0)A
where F is the force applied, Y is the Young's modulus of the material, ΔL is the change in length, L0 is the original length, and A is the cross-sectional area of the wire.

In this case, Y = 2.0 × 1011 N/m2, ΔL = 0.08 mm = 8.0 × 10-5 m, L0 = 1 mm = 10-3 m, and A = (π/4)(1 mm)2 = 7.85 × 10-7 m2.

Substituting these values into the equation, we get:
F = (2.0 × 1011 N/m2)(8.0 × 10-5 m)/(10-3 m)(7.85 × 10-7 m2) = 12.6 × 103 N

Therefore, the best choice is B, 12.6 × 103 N.

Question 2

Consider two steel rods,A and B.B has three times the area and twice the length of A,so Young's modulus for B will be what factor times Young's modulus for A?
A) 3.0
B) 0.5
C) 1.5
D) 1.0

Accepted Answer

Young's modulus is an intrinsic property of a material and does not depend on the geometry of the sample. Therefore, despite the differences in area and length between rods A and B, their Young's modulus will be the same.

Question 3

A tire stops a car by use of friction.What modulus should we use to calculate the stress and strain on the tire?
A) Young's modulus
B) compression modulus
C) shear modulus
D) bulk modulus

Accepted Answer

When a tire stops a car by use of friction, it experiences shear stress due to the friction force acting horizontally. Therefore, shear modulus is the best choice to calculate the stress and strain on the tire. Young's modulus is for axial stress and strain, compression modulus is for the stress and strain under compression, and bulk modulus is for volume stress and strain.

Question 4

What is the total mass of the Earth's atmosphere? (The radius of the Earth is 6.4 × 10⁶ m,and atmospheric pressure at the surface is 10⁵ N/m². ) A) 5 × 10¹⁶ kg B) 1 × 10¹⁸ kg C) 5 × 10¹⁸ kg D) 1 × 10²⁰ kg

Accepted Answer

To find the mass of the atmosphere, we need to first find its volume. We can use the formula for pressure at a depth in a liquid (which also applies to gases) to find the height of the atmosphere:

pressure = density × gravity × depth

Rearranging:

depth = pressure / (density × gravity)

Substituting in the given values:

depth = (10^5 N/m^2) / ((1.2 kg/m^3) × (9.8 m/s^2)) = 8.5 km

So the height of the atmosphere is about 8.5 km. To find the volume of the atmosphere, we need to multiply this height by the surface area of the Earth:

volume = 4/3 × π × (6.4 × 10^6 m)^3 × 8.5 km/6.4 × 10^6 m = 1.08 × 10^18 m^3

Finally, we can find the mass of the atmosphere by multiplying by its density:

mass = volume × density = 1.08 × 10^18 m^3 × 1.2 kg/m^3 = 5.04 × 10^18 kg, which is closest to answer choice C.

Question 5

A solid object is made of two materials,one material having density of 2 000 kg/m³ and the other having density of 5 500 kg/m³.If the object contains equal masses of the materials,what is its average density? A) 2 933 kg/m³ B) 3 750 kg/m³ C) 3 933 kg/m³ D) 7 500 kg/m³ E) more information is needed

Accepted Answer

The average density is the total mass divided by the total volume. Since the object contains equal masses of the two materials, the total mass is the sum of the masses of the two materials. The total volume is the sum of the volumes of the two materials. The density of the first material is 2000 kg/m3, and the density of the second material is 5500 kg/m3. The mass of the first material is equal to its density times its volume, and the mass of the second material is equal to its density times its volume. The total mass is therefore equal to the sum of the two masses, which is 2000 kg/m3 * V1 + 5500 kg/m3 * V2. The total volume is equal to the sum of the two volumes, which is V1 + V2. The average density is therefore equal to the total mass divided by the total volume, which is (2000 kg/m3 * V1 + 5500 kg/m3 * V2) / (V1 + V2). Since V1 = V2, the average density is equal to (2000 kg/m3 + 5500 kg/m3) / 2 = 3750 kg/m3.

Question 6

The Greenland ice sheet can be one km thick.Estimate the pressure underneath the ice.(The density of ice is 918 kg/m³. ) A) 9.0 × 10⁵ Pa (9 atm) B) 2.5 × 10⁶ Pa (25 atm) C) 4.5 × 10⁶ Pa (45 atm) D) 9.0 × 10⁶ Pa (90 atm)

Accepted Answer

Using the formula for pressure, P = density x gravitational acceleration x height, and plugging in the given values with the unit conversion of 1 km = 1000 m, we get:

P = (918 kg/m³) x (9.81 m/s²) x (1000 m)
P = 9.0 x 10¹⁶ Pa or 90 atm

Therefore, the best choice is D.

Question 7

Bar One has a Young's modulus that is bigger than that of Bar Two.This indicates Bar One:
A) is longer than Bar Two.
B) has a greater cross-sectional area than Bar Two.
C) has a greater elastic limit than Bar Two.
D) is made of material that is different from Bar Two.

Accepted Answer

Young's modulus is a material property that measures the stiffness of a solid material. If Bar One has a Young's modulus that is bigger than that of Bar Two, it indicates that the material of Bar One is different from that of Bar Two, as Young's modulus is independent of the shape and size of the material.

Question 8

In an elastic solid there is a direct proportionality between strain and:
A) elastic modulus.
B) temperature.
C) cross-sectional area.
D) stress.

Accepted Answer

In an elastic solid, the strain (deformation) is directly proportional to the applied stress. This relationship is described by Hooke's Law, which states that the amount a material deforms is directly proportional to the load applied to it, as long as the material remains within its elastic limit.

Question 9

The quantity "stress" expressed in terms of the fundamental quantities (mass,length,time)is equivalent to: A) MLT−¹. B) ML−¹T−². C) M²L−¹T−³. D) a dimensionless quantity.

Accepted Answer

The answer of The quantity "stress" expressed in terms of...

Question 10

The standard kilogram is a platinum-iridium cylinder 30.0 mm in height and 31.0 mm in diameter.What is the density of the material? A) 44.2 g/cm³ B) 43.3 g/cm³ C) 45.1 g/cm³ D) 10.0 g/cm³ E) 86.5 g/cm³

Accepted Answer

The density of the material can be calculated using the formula:density = mass/volumeThe mass of the cylinder is 1 kg, and the volume can be calculated using the formula for the volume of a cylinder:volume = πr^2hwhere r is the radius of the cylinder and h is the height.The radius of the cylinder is 15.5 mm, and the height is 30.0 mm.Substituting these values into the formula for the volume, we get:volume = π(15.5 mm)^2(30.0 mm) = 22.0 cm^3Substituting the mass and volume into the formula for the density, we get:density = 1 kg / 22.0 cm^3 = 45.5 g/cm^3The closest answer choice is A) 44.2 g/cm^3.

Question 11

A copper wire of length 5.0 m,cross sectional area 7.5 × 10−⁶ m² and Young's modulus 11 × 10¹⁰ N/m² has a 190-kg load hung on it.What is its increase in length? (g = 9.8 m/s²) A) 0.50 mm B) 11.7 mm C) 10.9 mm D) 11.3 mm E) 22.6 mm

Accepted Answer

We can use the formula 
ΔL = (F * L)/(A * Y)
where 
ΔL = increase in length 
F = force applied (190 kg * 9.8 m/s2 = 1862 N) 
L = length of wire (5.0 m) 
A = cross-sectional area of wire (7.5 × 10−16 m2) 
Y = Young's modulus (11 × 1010 N/m2)

Plugging in the values, we get 
ΔL = (1862 N * 5.0 m)/(7.5 × 10−16 m2 * 11 × 1010 N/m2) 
ΔL ≈ 0.0113 m = 11.3 mm

Therefore, the best choice is D, with an increase in length of 11.3 mm.

Question 12

The pressure inside a commercial airliner is maintained at 1.00 atm (10⁵ Pa).What is the net outward force exerted on a 1.0 m × 2.0 m cabin door if the outside pressure is 0.30 atm? A) 140 N B) 1 400 N C) 14 000 N D) 140 000 N

Accepted Answer

The answer of The pressure inside a commercial airliner is...

Question 13

The bulk modulus of a material,as a meaningful physical property,is applicable to which of the following?
A) only solids
B) only liquids
C) only gases
D) solids,liquids and gases

Accepted Answer

The bulk modulus is a measure of resistance to compression under hydrostatic pressure. It is applicable to solids, liquids, and gases because all three can experience hydrostatic pressure. Therefore, the correct choice is D.

Question 14

Which state of matter is associated with the very highest of temperatures?
A) liquid
B) plasma
C) gas
D) solid

Accepted Answer

Plasma is the state of matter that is associated with the highest temperatures. Plasma occurs when a gas is heated to a very high temperature and the electrons become separated from their parent atoms. This creates a state of matter that consists of charged particles, which behave differently than neutral particles in a gas, liquid or solid state. Plasma is the form of matter found in stars, lightning, and in some types of flames.

Question 15

The quantity "pressure" expressed in terms of the fundamental quantities (mass,length,time)is equivalent to: A) MLT−¹. B) ML−¹T−². C) M²L−¹T−³. D) a dimensionless quantity.

Accepted Answer

The answer of The quantity "pressure" expressed in terms of...

Question 16

A solid object is made of two materials,one material having density of 2 000 kg/m³ and the other having density of 5 000 kg/m³.If the object contains equal volumes of the materials,what is its average density? A) 2 857 kg/m³ B) 3 500 kg/m³ C) 4 500 kg/m³ D) 7 000 kg/m³ E) more information is needed

Accepted Answer

The average density is calculated by taking the mean of the two densities since the volumes are equal: (2000 kg/m³ + 5000 kg/m³) / 2 = 3500 kg/m³.

Question 17

The quantity "strain" expressed in terms of the fundamental quantities (mass,length,time)is equivalent to: A) MLT−¹. B) ML−¹T−². C) M²L−¹T−³. D) a dimensionless quantity.

Accepted Answer

Strain is defined as the ratio of change in dimension to the original dimension, which does not have any units or dimensions, making it a dimensionless quantity.

Question 18

A stonecutter's chisel has an edge area of 0.45 cm².If the chisel is struck with a force of 48 N,what is the pressure exerted on the stone? A) 1 067 Pa B) 10 670 Pa C) 106 700 Pa D) 1 067 000 Pa E) 533 500 Pa

Accepted Answer

The answer of A stonecutter's chisel has an edge area...

Question 19

When water freezes,it expands about nine percent.What would be the pressure increase inside your automobile engine block if the water in there froze? (The bulk modulus of ice is 2.0 × 10⁹ Pa,and 1 atm = 1.0 × 10⁵ Pa. ) A) 18 atm B) 270 atm C) 1 080 atm D) 1 800 atm

Accepted Answer

The answer of When water freezes,it expands about nine percent.What...

Question 20

A uniform pressure of 6.9 × 10⁵ N/m² is applied to all six sides of a copper cube.What is the percentage change in volume of the cube? (for copper,B = 14 × 10¹⁰ N/m²) A) 1.2 × 10−² % B) 0.9 × 10−² % C) 2.0 × 10−² % D) 0.5 × 10−³ % E) 0.0 × 10−³ %

Accepted Answer

The answer of A uniform pressure of 6.9 × 10⁵...

Quiz 9: Solids and Fluids

How large a force is necessary to stretch a 1-mm-diameter steel wire (Y = 2.0 × 10¹¹ N/m²) by 8.0%?

Consider two steel rods,A and B.B has three times the area and twice the length of A,so Young's modulus for B will be what factor times Young's modulus for A?

A tire stops a car by use of friction.What modulus should we use to calculate the stress and strain on the tire?

What is the total mass of the Earth's atmosphere? (The radius of the Earth is 6.4 × 10⁶ m,and atmospheric pressure at the surface is 10⁵ N/m². )

A solid object is made of two materials,one material having density of 2 000 kg/m³ and the other having density of 5 500 kg/m³.If the object contains equal masses of the materials,what is its average density?

The Greenland ice sheet can be one km thick.Estimate the pressure underneath the ice.(The density of ice is 918 kg/m³. )

Bar One has a Young's modulus that is bigger than that of Bar Two.This indicates Bar One:

In an elastic solid there is a direct proportionality between strain and:

The quantity "stress" expressed in terms of the fundamental quantities (mass,length,time) is equivalent to:

The standard kilogram is a platinum-iridium cylinder 30.0 mm in height and 31.0 mm in diameter.What is the density of the material?

A copper wire of length 5.0 m,cross sectional area 7.5 × 10−⁶ m² and Young's modulus 11 × 10¹⁰ N/m² has a 190-kg load hung on it.What is its increase in length? (g = 9.8 m/s²)

The pressure inside a commercial airliner is maintained at 1.00 atm (10⁵ Pa) .What is the net outward force exerted on a 1.0 m × 2.0 m cabin door if the outside pressure is 0.30 atm?

The bulk modulus of a material,as a meaningful physical property,is applicable to which of the following?

Which state of matter is associated with the very highest of temperatures?

The quantity "pressure" expressed in terms of the fundamental quantities (mass,length,time) is equivalent to:

A solid object is made of two materials,one material having density of 2 000 kg/m³ and the other having density of 5 000 kg/m³.If the object contains equal volumes of the materials,what is its average density?

The quantity "strain" expressed in terms of the fundamental quantities (mass,length,time) is equivalent to:

A stonecutter's chisel has an edge area of 0.45 cm².If the chisel is struck with a force of 48 N,what is the pressure exerted on the stone?

When water freezes,it expands about nine percent.What would be the pressure increase inside your automobile engine block if the water in there froze? (The bulk modulus of ice is 2.0 × 10⁹ Pa,and 1 atm = 1.0 × 10⁵ Pa. )

A uniform pressure of 6.9 × 10⁵ N/m² is applied to all six sides of a copper cube.What is the percentage change in volume of the cube? (for copper,B = 14 × 10¹⁰ N/m²)

Quiz 9: Solids and Fluids

How large a force is necessary to stretch a 1-mm-diameter steel wire (Y = 2.0 × 1011 N/m2) by 8.0%?

Consider two steel rods,A and B.B has three times the area and twice the length of A,so Young's modulus for B will be what factor times Young's modulus for A?

A tire stops a car by use of friction.What modulus should we use to calculate the stress and strain on the tire?

What is the total mass of the Earth's atmosphere? (The radius of the Earth is 6.4 × 106 m,and atmospheric pressure at the surface is 105 N/m2. )

A solid object is made of two materials,one material having density of 2 000 kg/m3 and the other having density of 5 500 kg/m3.If the object contains equal masses of the materials,what is its average density?

The Greenland ice sheet can be one km thick.Estimate the pressure underneath the ice.(The density of ice is 918 kg/m3. )