Physics Answers

A bi-concave lens has a radius of curvature of one side equal to 10.5cm and on the other side equal to 15.0cm.If the lens is made of crown glass(n=1.52), what is the focal length of the lens?

A uniform solid ball has some turns of light string wound around it. If the end of the string is fixed and the ball is allowed to fall under gravity, what is the acceleration of the center of the ball?

A 1 kg object is located at a distance of 6.4x106 m from the center of a larger object whose mass is 6.0x1024 kg.

a. What is the size of the force acting on the smaller object?

 b. What is the size of the force acting on the larger object?

1. A 0.45-caliber bullet with m = 0.133 kg hurled from a gun’s muzzle at 950 m/s.

2. A 0.126-lb tennis ball has been shot up from rest with a racket. Suppose the ball reaches a height of 5.5 m. Calculate the net impulse of the force

3. On average, a standard 57.0-g tennis ball is said to be in contact with the tennis racket for 30 milliseconds. Suppose that a serve is done with a speed of 262.8 kph. What amount of force was exerted on the ball during the serve?

4. A block with mass equal to 12 000 g slid across a frictionless surface at 37.0 m/s and hit another block at rest. After the impact, they bounced off of each other with respective velocities of 42.502 mph and 8.948 mph. Determine the mass of the second block.

5. Two balls of masses 10.0 kg and 20.0 kg collided such that the 10.0-kg ball moved with a velocity of 15.66 mph. If the second ball was at rest prior to the collision, what is its final velocity?

 6. Infer the importance of the Conservation of Momentum.

A railway track that is 50 m long, with initial temperature of 10 °C is subjected to a great heat. How much will it expand when its temperature is tripled [α= 13 ´ 10^-6 / °C]?

The two identical charges have a magnitude of ±1.00×10^-6 Coulombs which separated by 1 cm. What is the magnitude of the force separating the charges?

Problem 1. A batter hits a baseball so that it leaves the bat at speed vo = 37.0m/s at an angle αo = 53.1◦, at a location where g = 9.80m/s2.

A narrow beam of 100 MeV neutrons, with a intensity 10 to the power 5

n/cm2

.s , is

normally incident on an aluminum foil. The elastic scattering cross

section of aluminum for 100 MeV neutrons is 0.95 barns. The density of

aluminum is 2.7 g/cm3

. How thick must the aluminum foil be in order to

reduce the number of unscattered neutrons emerging from the foil by

three orders of magnitude?

A standing wave, generated on a string of length L, is represented by the following mathematical expression y(x,t) = 10 sin⁡(2πx) cos⁡(15πt). At what times would all the elements of the string have zero displacement [y(x,?) = 0]?

If the satellite S2 at a distance 6850000 m from the center of the earth, determined the orbital period of the satellite.

[Mass of earth, M = 5.97x 〖10〗^24kg, G=6.67x〖10〗^(-11) 〖Nm〗^2 〖kg〗^(-2)