Physics Answers

Using Lagrange's method,show that angular momentum about a vertical axis through the point of support of a spherical pendulum is conserved?

The viscous drag force F, on a sphere of radius r, moving through a fluid with velocity v, can be expressed as F = 6PLrv, where L is the coefficient of viscosity of the fluid and P = pie(22/7). What are the base units of L?

A sphere of radius a, moving with velocity v, under streamline conditions in a viscous fluid experiences a retarding force F, given by F = kav, where k is a constant. What are the base units of k?

What are the base units of k so that the equation of velocity (v) = k x density

The equation s = ut + 1/2 at² relates the displacement s, initial velocity u, time t and acceleration a, of a particle under uniform accelerated motion. Show that the equation is homogeneous. Is it consistent and physically correct?

#9. The normal human body has an average core or interior temperature of 37C. At a skin temperature of 34 C, how much heat is removed through conduction? Assume a thermal conductivity of unperfused (i.e. bloodless) tissue of 18 (Cal x cm)/(m^2 x hr x C), 3 cm thickness of the tissue between the interior and the exterior of the body and 1.5 m2 total surface area of the human body. 

Choices: 

1. 36 Cal/hr
2. 29 Cal/hr
3. 27 Cal/hr
4. 18 Cal/hr
5. 22.5 Cal/hr

#10. If the human body needs to get rid of 150 Cal of heat per hour through conduction alone, at what temperature should the skin be if a core temperature of 37C is maintained? Assume a thermal conductivity of unperfused (i.e. bloodless) tissue of 18 (Cal x cm)/(m^2 x hr x C), 3 cm thickness of the tissue between the interior and the exterior of the body and 1.5 m2 total surface area of the human body. 

1. 20.333 C  
2. 20.889 C 
3. 22 C 
4. 19.778 C 

The normal human body has an average core or interior temperature of 37C∘. At a skin temperature of 34 C∘, how much heat is removed through conduction? Assume a thermal conductivity of unperfused (i.e. bloodless) tissue of 18 (Cal x cm)/(m^2 x hr x C), 3 cm thickness of the tissue between the interior and the exterior of the body, and 1.5 m2 total surface area of the human body. 

Choices:

• 36 Cal/hr
• 29 Cal/hr
• 27 Cal/hr
• 18 Cal/hr
• 22.5 Cal/hr

Calculate induced emf induced in a coil having radius 2 cm and containing 320 turns placed in a time varying magnetic field. The plane of coil is perpendicular to the magnetic field whose expression for is given by:

B=(0. 0120T/s)t + (0.00035T/s⁴)t⁴

The coil is also connected to 300 Ω external resistor.

Suppose earth and moon carry + charges of equal magnetude. How large would charge need to be to produce an electrostatic repulsion equal 1% of gravitational attraction between the 2 bodies?

A converging lens of focal length 20.0 cm forms an image of each of two objects placed (a) 40.0 cm and 

(b) 15.00 cm in front of the lens. In each case, find the image distance and describe the image