Physics Answers

A car is driven west for a distance of 50 km, then north for 30 km, and then in direction 30° east of

north for 25 km. Determine the total displacement of the car from its starting point by drawing the

vector diagram.

The potential energy of a system of two atoms is given by the expression, 𝐔 = −𝐀 𝐫 𝟑 + 𝐁 𝐫 𝟖 A stable molecule is formed with release of 10 eV of energy when the interatomic distance is 3 A°. Determine the force needed to dissociate this molecule into atoms and the interatomic distance at which the dissociation occurs

Computation:

A 50000 g object accelerates with a force of 500 newtons. Find the acceleration of the object.

A man standing on the roof of a building throws a ball with a velocity 18.0 ms-1 at an angle 50o from the horizontal. The height of the building is 35.0 m. (Given g = -9.81 ms-2) Calculate:

(i) the maximum height of the ball from the ground,

(ii) the magnitude of the velocity of the ball just before it strikes the ground.

A satellite is projected near the surface of Earth so that it has a certain speed that can orbit the Earth. Calculate the speed of the satellite and the time for 1 complete rotation around the Earth. (Given, ME = 6 x 1024 kg, RE = 6.38 x 106 m, G = 6.67 x 10-11 Nm2kg-2)

A fisherman on a stationary boat jumps off onto a jetty with a velocity of 1.5 ms-1, causing the boat to move backwards.

(i) If the mass of the fisherman and the boat are 65 kg and 450 kg respectively, determine the velocity of the boat. (ii) If the fisherman’s feet are in contact with the jetty for 10 ms, determine the magnitude of the average force exerted on his feet.

1. A series circuit consisting of 3 resistors R₁ = 8.0Ω, R₂ = 12.0Ω, and R₃ = 4.0Ω is connected to a 24.0 V terminal voltage. a. Calculate the equivalent resistance, b. Calculate the current through each resistor, c. Calculate the potential drop across each resistor.
2. Three resistors are connected in parallel, R₁ = 2.0Ω, R₂ = 5.0Ω, and R₃ = 10.0Ω attached to a 1.25V voltage source. a. Calculate the equivalent resistance, b. Calculate the current supplied by the source to the parallel circuit, c. Calculate the current in each resistor.

What would be the diameter of the erth if it had the density of a neutron star?

When light from a red laser, with a wavelength of 632 nm, is incident on a certain double slit, a particular interference pattern is observed. The laser light is replaced by a beam of electrons, all with the same energy, and exactly the same interference pattern is observed. What is (a) the wavelength, (b) frequency, and (c) energy of the electrons?

A small 10 mm diameter permanent magnet produces a field of 100 mT. The field drops away rapidly with

distance and is negligible more than 1 mm from the surface. If this magnet moves at a speed of 1 m/s through a 100-turn coil of length 1 mm and diameter just larger than the magnet, what is the EMF induced?