Other Physics Answers

12. An astronaut experiences a force of gravity on Earth of 800 N. Neptune has 17 times the mass and 3.9 times the radius of Earth. What would the astronaut weigh, in newtons, on Neptune?

A wire of length 0.50 m is fixed horizontally between two supports separated by 0.50 m. When a

mass of 8 kg hangs from the middle of the wire, the mid-point sags by 1 cm. The diameter of the

wire is 2.8 mm. Calculate the Young’s modulus of the wire.

water is not to spill, what is the minimum velocity the pail can have? (b) How much time per revolution is this equivalent to? 

A train slows from 108 km per hour with a uniform acceleration of 5 m per second square. How long will it take to reach 18 km per hour and the what is the distance covered.

One of the tallest buildings in the world is the Taipei 101 in Taiwan, at a height of 1671 feet. Assume that this height was measured on a cool spring day when the temperature was 15.5⁰C. You could use the building as a sort of giant thermometer on a hot summer day by carefully measuring its height. Suppose you do this and discover that the Taipei 101 is 0.471 foot taller than its official height. What is the temperature, assuming that the building is in thermal equilibrium with the air and that its entire frame is made of steel? (coefficient of linear expansion of steel is 3.5x10^-5/⁰C)

What, roughly, is the percent uncertainty in the volume of a spherical beach ball whose radius is r =

(0.84 ± 0.04) m?

The volume of liquid V flowing through a pipe of radius r in time t is given by:

V / t = πr 4 (P 1 – P 2 ) / 8ηL

where P 1 and P 2 are the pressures at each end of the pipe, L is its length and η (eta) is a physical quantity

called the viscosity of liquid. Use the following to determine η together with its uncertainty.

r = (0.43 ± 0.01) mm

P 1 = (1.150 ± 0.005) X 10 5 Pa

P 2 = (1.000 ± 0.005) X 10 5 Pa

L = (5.5 ± 0.1) cm

V = (10.0 ± 0.1) cm 3

t = (4.0 ± 0.1) s

Consider the following data to find the Young’s Modulus, E, of a steel wire of length l and diameter d,

given that:

E = 4 Mgl / πed 2

and:

Length of wire (l) = (3.025 ± 0.005) m

Diameter of wire (d) = (0.84 ± 0.01) mm

Mass supported by wire (M) = (5.000 ± 0.002) kg

Extension caused (e) = (1.27 ± 0.02) mm

Acceleration of free fall (g) = (9.81 ± 0.01) ms -2

Two lengths are recorded as (1.873 ± 0.005) mm and (1.580 ± 0.005) mm. What is the maximum

possible value of the sum of the two lengths and what is the maximum possible value of the difference

between the two lengths? What is the fractional uncertainty in both the sum of the two lengths and the

difference between the two lengths?

Find υ and the uncertainty in υ if

υ = (a – b) d 2 / (q √ T )

and a = (1.83 ± 0.01) m, b = (1.65 ± 0.01) m, d = (0.001 06 ± 0.000 03) m, q = (4.28 ± 0.05) s and

T = (3.7 ± 0.1) X 10 3 s.