Physics Answers

What is the buoyant force of a small can with a volume of 0.00005 m3 when completely submerged in water?

A plane weighing 233 kN lands on a aircraft carrier. The plane is moving horizontally at 69.6 m/s when its tailhook grabs hold of the arresting cabels. The cabels bring the plane to a stop in a distance of 84.0m. a) How much work is done on the plane by the arresting cabels in MJ? b) What is the force(assumed constant) exerted on the plane by the cabels?

A proton moves through a uniform magnetic field of magnitude 2.0 μT at a speed of 5.00x10^6 m/s.

(a) What is the magnitude of the maximum magnetic force it can experience?

(b) If the proton is replaced by an electron, will it experience the same maximum force?

A bus is moving at 5.0 m/s when a passenger walks forward at 1.5 m/s relative to the bus. How fast is this passenger moving as seen and measured by (a) a person waiting at the bus stop and (b) the driver of the bus?

1. The half-life of an isotope is 5 years. What fraction of the isotope will remain after 20 years?

2. The half-life of Bi-210 is 5 days. What percentage of a sample of Bi-210 will remain after 10 days?

The force between two electrical charges is 0.4 N. What would be the force if the charges are doubled, and the distance between them increased by 100%? 

An underwater scuba diver sees the Sun at an apparent angle of 47.0° above the horizontal. What is the actual elevation angle of the Sun above the horizontal? (Use 1.333 for the index of refraction of water.)

 ° above the horizon

Assume a transparent rod of diameter d = 6.06 𝜇m has an index of refraction of 1.25. Determine the maximum angle 𝜃 for which the light rays incident on the end of the rod in the figure below are subject to total internal reflection along the walls of the rod. Your answer defines the size of the cone of acceptance for the rod.

1.      The speed of the bullet (m = 50g) and the speed of an electron ( m = 9.1 * 10^-28g) are measured to be the same, namely 300 m/s, with an uncertainty of 0.01%. With what fundamental accuracy could we have located the position of each, if the position is measured simultaneously with the speed in the same expt.?

1.      A small object of mass 1 mg is confined to move between two rigid walls separated by 2 cm. (a) Calculate the minimum speed of the object. (b) If the speed of the object is 4 cm/s, find the corresponding value of ‘n’.