Because: Some of the work done by the machine is used to overcome the friction created by the use of the machine. ... Work output can never be greater than work input. Machines allow force to be applied over a greater distance, which means that less force will be needed for the same amount of work.

6 0

3 years ago

What is the speed of a commercial jet which travels form New York to Los Angeles (4800) in 6 hours

Colt1911 [192]

Answer:

$Speed = 800km}/hr$

Explanation:

Given

$Distance = 4800km$

$Time = 6hr$

Required

Determine the speed of the jet

The speed is calculated as:

$Speed = \frac{Distance}{Time}$

Substitute 4800 km for Distance and 6hr for Time

$Speed = \frac{4800km}{6hr}$

$Speed = 800km}/hr$

<em>Hence, the speed of the commercial jet is 800km/hr</em>

8 0

3 years ago

calculate the spring constant if a weight of 250N is added to a spring which increases in length by 20cm

ZanzabumX [31]

Since, F = k . ∆x

Therefore, k = F / ∆x = 250 / 0.2 = 1250 N/m

(ps: convert 20 cm into 0.2 m)

8 0

3 years ago

What are the foci of the ellipse given by the equation 100x^2 + 64y^2 = 6 400?

NikAS [45]

The equation of our ellipse is:

$100 x^2 + 64 y^2 = 6400$ (1)

First, let's reduce the equation of the ellipse to the standard form:

$\frac{x^2}{a^2}+ \frac{y^2}{b^2}=1$

To do that, we should divide both terms of equation (1) by 6400, and we get:

$\frac{x^2}{64}+ \frac{y^2}{100}=1$

This is a vertical ellipse (because $b^2 \ \textgreater \ a^2$ ) centered in the origin, and so the distance of its foci from the origin (on the y axis) is given by

$c= \sqrt{b^2-a^2}= \sqrt{(100)-(64)}=6$

Therefore, the position of the two foci is (0,6) and (0,-6)

8 0

3 years ago