All categories

3 years ago

A child carries a 3N book at a constant velocity 4 meters across a horizontal floor. What is the net work done?

1 answer:

5 0

Note that 4 m (meters) has the units of distance, not velocity.

By definition,
Work = Force x Distance
Therefore if a 3 N book is carried over a distance of 4 m, the work done is
3 *3 4 = 12 J

Answer: 12 J

You might be interested in

3m/s for 12 seconds how dar would he walk

Sunny_sXe [5.5K]

I think 36m/12s because 3×12 =36

4 0

3 years ago

(a) When a battery is connected to the plates of a 8.00-µF capacitor, it stores a charge of 48.0 µC. What is the voltage of the

frosja888 [35]

Answer:

a.6 V

b.24 V

Explanation:

We are given that

a. $C=8\mu F=8\times 10^{-6} F$

$1\mu =10^{-6}$

Q= $48\mu C=48\times 10^{-6} C$

We know that

$V=\frac{Q}{C}$

Using the formula

$V=\frac{48\times 10^{-6}}{8\times 10^{-6}}=6 V$

b. $Q=192\mu C=192\times 10^{-6} C$

$V=\frac{192\times 10^{-6}}{8\times 10^{-6}}=24 V$

8 0

2 years ago

A Pitot-static tube is mounted on a 2.5 cm pipe where oil (???? = 860 kg/m3, ???? = 0.0103 kg/m·s) is flowing. The Pitot tube is

emmasim [6.3K]

Answer:

$\dot{V}=0.0733 \,m^3.s^{-1}$

Explanation:

Given:

density, $\rho=860\,kg.m^{-3}$

diameter of the pipe, $d=2.5\times 10^{-2}m$

pressure difference, $\Delta P=95.8\times 10^{5}\,Pa$

In case of pitot tube, the velocity is given by:

$v=\sqrt{\frac{2.\Delta P}{\rho} }$

$v=\sqrt{\frac{2\times 95.8\times 10^{5}}{860} }$

$v=149.26\,m.s^{-1}$

Now we know that volumetric flow rate is given as:

$\dot{V}=a.v$

where :

a= cross sectional area of the pipe

v= velocity of flow

$\dot{V}=(\pi\times \frac{(2.5\times 10^{-2})^2}{4} ) \times 149.26$

$\dot{V}=0.0733 \,m^3.s^{-1}$

4 0

2 years ago

Which of the following are appropriate acceleration units? km/hr2 m/s/s ft/s miles/hr/min sec/km/m

Reika [66]

I think it is m/s/s or miles/hr/min

8 0

3 years ago

Read 2 more answers

A basic physics question

Anna71 [15]

No,kinetic energy cannot be negative since its given by KE=mv²,mass cannot be negative and the square of speed cannot b negative.

Yes,any force opposing motion or displacement does negative work. They are often referred to as resistive forces (friction,air resistance,drag...)

Nope it does not, it just forces the object to move in a circular path known as a centripetal force. It can accelerate an object by changing it's direction but not it's speed.

No it cannot,If an object is sliding on the table (assuming it is not an incline), then most probably that normal force cancels out the weights effect or assuming there is an incline, it cancels the weight's y component.

$w = f.d.cos \alpha = f.d.cos90 = 0$