a dad expends 200 joules of work pushing a stroller up a hill. he produces 125 j of work. how efficient is he being?

If the horizontal component of a vector is 6 m/s and the vertical component is also 6 m/s, what is the resultant value of the ve

BlackZzzverrR [31]

Resultant force= (2*6^2)^(1/2)
=8.5m/s
answer is B.

6 0

3 years ago

We know that the magnitudes of the negative charge on the electron and the positive charge on the proton are equal. Suppose, how

TEA [102]

Answer:3,45 x 10^9 N

Explanation: We have considered the total charge for each coin , this is the total atoms x 29 electrons for cooper and multiplier by electron charge, the total charge for each coin is 0,464 C

Finally we use the Coulomb law,

F=k Q/ (r)^2

6 0

3 years ago

The gravitational force,F, on a rocket at a distance,r, from the center of the earth isgiven byF=kr2wherek= 1013N·km2. (Newton·k

Brrunno [24]

Answer:

The gravitational force changing velocity is

$\frac{dF}{dt}=-8\frac{N}{s}$

Explanation:

The expression for the gravitational force is

$F=\frac{k}{r^{2}}\\\\k=10x10^{13} N*km^{2}\\\\r=10x10^{4} km\\\\V=0.4 \frac{km}{s}$

Differentiate the above equation

$\frac{dF}{dt}=\frac{k}{r^{2}}\\\frac{dF}{dt}=k*r^{-2}\\\frac{dF}{dt}=-2*k*r^{-3} \frac{dr}{dt}\\\frac{dF}{dt}=\frac{-2k}{r^{3}}\frac{dr}{dt}$

The velocity is the distance in at time so

$V=\frac{dr}{dt}=0.4 \frac{km}{s}$

$\frac{dF}{dt}=\frac{-2*k}{r^{3}}*0.4\\\frac{dF}{dt}=\frac{-8*10x^{13}N*km^{2} }{(10x10^{4}) ^{3}} \\\frac{dF}{dt}=\frac{-8x10^{12} }{1x10^{12}}$

$\frac{dF}{dt}=-8\frac{N}{s}$

8 0

3 years ago

A driver looks at her dashboard and reads that she is traveling at 100 kilometers per hour. What does this measurement represent

Dmitry_Shevchenko [17]

The answer is C!! 100 kilometers per hour is an average speed.

6 0

3 years ago

Read 2 more answers

What’s important about physical health

coldgirl [10]

Answer:

Physical activity or exercise can improve your health and reduce the risk of developing several diseases like type 2 diabetes, cancer and cardiovascular disease. Physical activity and exercise can have immediate and long-term health benefits. Most importantly, regular activity can improve your quality of life.

Explanation:

<h2>hope it is helpful for you </h2><h2>keep smiling </h2>

4 0

2 years ago