Mechanics | Relativity Answers

At the surface of Jupiter’s moon Io the acceleration due to gravity is g=1.81 m/s2 . A watermelon weighs 44.0 N at the surface of the earth. a) What is the mass on the earth’s surface? b) What are its mass and weight on the surface of Io? 

QUESTION 1

A wave out in the deep ocean has an amplitude of 1.51 m, a wavelength of 212 m and a period of 14.3 s

What is the speed of such a wave? (in ms-1 to 3 s.f)

2 pts) A light wave is initially polarized in the +y direction and has intensity 1.0 W/m^2. It encounters a polarizer whose axis is 60 degrees counterclockwise from the +x axis. After the wave has emerged from the polarizer, i.

In which direction does its electric field point?

A. +x

B. +y

C. +z

D. 30° counterclockwise from +x

E. 60° counterclockwise from +x

ii. What is its intensity?

A. 0.25 W/m2

B. 0.50 W/m2

C. 0.75 W/m2

D. 0.87 W/m2

E. 1.0 W/m2

A uniform 3.0 kg disk of radius 30 cm is rotating around its central axis at an angular speed of 72 rad/s. At time t = 0, a man begins to slow it at a uniform rate until it stops at t = 20 s. (a) Find its angular acceleration. (b) By time t- 10 s, how much work had the man done? (c) For full 20 s, at what average rate did the man do work?

A 5 kg object is located at a distance of 9.0 x109 km from the center of a larger object whose mass is 2.0 x 1030 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?

c. What is the acceleration of the smaller object when it is released?

d. What is the acceleration of the larger object when it is released?

A person is holding a 5.0 kg mass in one hand as shown in the figure above.

You can ignore the mass of the forearm itself.What is the force exerted by the bicep in order to keep the arm horizontal?(in N to 2s.f)

A sound wave of frequency 300Hz travels with speed 340ms–¹along the negative x-direction. Each point of the medium moves up and down through a total distance of 5.0mm. Determine the necessary parameters to represent the wave mathematically.

A piece of metal has a mass of 200 g in air and 170 g when immersed in water. Calculate its volume and density. [Density of water is 1000 kgm-3. Take g=9.8 ms-2 ]

Joanne drives her car with a mass of 1000 kg at a speed of 20 m/s. Show that to bring her car to a halt in 10 s, road friction must exert a force of 2000 N on the car. 

the earth pulling down on a 12kg rock during the 3.0s it takes to fall a cliff?