Ask question

Ask question

All categories

3 years ago

11

Martha is cycling at a speed of 20 kilometers per hour. How long will it take her to cover a distance of 60 kilometers? speed=di

stancetime

2 answers:

ser-zykov [4K]3 years ago

7 0

It will take 3 hours hope it helped :D

aivan3 [116]3 years ago

6 0

It will take 3 hours

You might be interested in

A child\'s top is held in place, upright on a frictionless surface. The axle has a radius of r = 2.96 mm. Two strings are wrappe

sladkih [1.3K]

Answer:

Explanation:

Given

radius r=2.96 mm

Tension T=2.4 N

time taken=0.74 s

Let $\alpha$ be the angular acceleration

$2 T\times r=I\times \alpha$

$2\times 2.4\times 2.96\times 10^{-3}=0.5\times m\times (2.96\times 10^{-3})^2\times \alpha$

$\alpha =\frac{4\times 2.4}{m\times 2.96\times 10^{-3}}$

$\alpha =\frac{3.24\times 10^3}{m} rad/s^2$

$\omega =\omega _0+\alpha \cdot t$

$\omega =0+\frac{3.24\times 10^3}{m}\times 0.74$

$\omega =\frac{2.4\times 10^3}{m} rad/s$

Angular momentum

$L=I\omega$

$L=0.5\times mr^2\times \omega$

$L=0.5\times m\times (2.96\times 10^{-3})^2\times \frac{2.4\times 10^3}{m}$

$L=0.01051 kg-m^2/s$

4 0

3 years ago

This question is about sound waves and light waves.

kenny6666 [7]

Answer:

you had it right

Explanation:

4 0

3 years ago

Read 2 more answers

Which of the following equations represents the law of universal gravitation

Xelga [282]

<span>Newton's law of universal gravitation is an INVERSE SQUARE LAW, which rules out C and D.It is proportional to the masses involved, which rules out B.A could be seen as one form of the lawF=G m1 m1/r^2Though I recognise it more as F=G m1 m2/r^2.G is the universal gravity constant and is distinct from g which is the acceleration of gravity LOCAL to a planet or moon. So, g is LOCAL, G is universal.Newton was a smart bloke, as are all these scientists whose names frequently appear.
</span>

8 0

3 years ago

Am needing help with this!!! Please hell

Yuki888 [10]

Answer:

ology

Explanation:

5 0

3 years ago

A battery is a device that produces electricity by transforming chemical energy into electrical energy. a battery does work on e

r-ruslan [8.4K]

(Missing question is: which of the following statements are true?)

a) A battery does work on electric charges to bring them to a position of higher electric potential energy so that they can flow through a circuit to a lower potential energy --> TRUE
That's true: the battery does the work to move the charges to one end of its terminal thus creating a potential difference between the two terminals. Then, when it is connected to the circuit, charges start to flow to the terminal at lower potential (through the circuit)

b) the potential difference between the terminals of a battery, when no current flows to an external circuit, is referred to as the terminal voltage --> FALSE
This is false: when no current flows, it is called e.m.f. (electromotive force)

c) <span>the internal resistance of a battery decreases with decreasing temperature
--> TRUE
In fact, the dependence of a resistance with the temperature is:
</span> $R=R_0 [1+\alpha(T-T_0)]$
with $\alpha$ being generally positive, therefore the value of the resistance is proportional to T, and when T decreases, R decreases as well.

d) a battery is a device that produces electricity by transforming chemical energy into electrical energy --> TRUEThat's true: a battery uses chemical reactions to create a potential difference between the two terminals that can be exploited to make charges flowing through a circuit.

3 0

4 years ago