Ask question

Ask question

All categories

2 years ago

11

A cheetah runs 900 meters in 30 seconds. how fast is it going?

1 answer:

Serga [27]2 years ago

7 0

900 meters/30 seconds= 30 meters/second

You might be interested in

Which changes do not involve forming or breaking chemical bonds? rusting and cutting burning and melting burning and digesting b

r-ruslan [8.4K]

Answer:

boiling and melting!

Explanation:

These do not make any changes chemically to the substance.

Hope this helps!

6 0

3 years ago

a spring is used to launch a ball vertically into the air. the spring has a spring constant of 200N/m and is compressed by 5 cm.

zhannawk [14.2K]

Answer:

2.55 m

Explanation:

Elastic energy = gravitational energy

½ kx² = mgh

h = kx² / (2mg)

h = (200 N/m) (0.05 m)² / (2 × 0.010 kg × 9.8 m/s²)

h = 2.55 m

8 0

3 years ago

A strong lightning bolt transfers an electric charge of about 31 C to Earth (or vice versa). How many electrons are transferred?

olchik [2.2K]

Answer:

$m=5.78\times 10^{-3}\ g$

$n_e=1.935\times 10^{20}$ is the no. of electrons

Explanation:

Given:

quantity of charge transferred, $Q=31\ C$

<u>No. of electrons in the given amount of charge:</u>

As we have charge on one electron $1.602\times 10^{-19}\ C$

so,

$n_e=\frac{Q}{e}$

$n_e=\frac{31}{1.602\times 10^{-19}}$

$n_e=1.935\times 10^{20}$ is the no. of electrons

Now if each water molecules donates one electron:

Then we require $n=1.935\times 10^{20}$ molecules.

<u>Now the no. of moles in this many molecules:</u>

$n_m=\frac{n}{N_A}$

where

$N_A=6.022\times 10^{23}$ Avogadro No.

$n_m=\frac{1.935\times 10^{20}}{6.022\times 10^{23}}$

$n_m=3.213\times 10^{-4}\ moles$

We have molecular mass of water as M=18 g/mol.

<u>So, the mass of water in the obtained moles:</u>

$n_m=\frac{m}{M}$

where:

m = mass in gram

$3.213\times 10^{-4}=\frac{m}{18}$

$m=5.78\times 10^{-3}\ g$

7 0

3 years ago

A marble slides without friction in a vertical loop around the inside of a smooth, 28.6 cm diameter horizontal pipe. The marble'

Leviafan [203]

Answer:3.49 m/s

Explanation:

Given

Speed of marble at Bottom $v=4.22 m/s$

Diameter of loop $d=28.6 cm$

As Energy is conserved therefore Energy at top is equal to energy at bottom

$E_T=E_B$

$\frac{mv^2}{2}+mgh=\frac{mv_0^2}{2}$ ,where $v_0$ is the velocity at bottom

$\frac{v^2}{2}+gh=\frac{v_0^2}{2}$

$v_0^2=v^2+2gh$

$v^2=v_0^2-2gh$

$v=\sqrt{v_0^2-2gh}$

$v=\sqrt{4.22^2-2\times 9.8\times 0.286}$

$v=\sqrt{17.8084-5.6056}$

$v=3.49 m/s$

7 0

3 years ago

It takes 300 newtons of force and a distance of 20 meters for a moving car to come to stop

Andrei [34K]

The answer is 15 I think.

7 0

3 years ago