Help..... disregard my answers...plz help

On the asteroid Cere, the acceleration due to gravity is about 0.27 m/s^2. How long would it take a ball to fall to the ground i

KiRa [710]

Answer:

F. 25.82 s

Explanation:

Given:

Δy = 90 m

v₀ = 0 m/s

a = 0.27 m/s²

Find: t

Δy = v₀ t + ½ at²

90 m = (0 m/s) t + ½ (0.27 m/s²) t²

t = 25.82 s

7 0

3 years ago

What is the period of a simple pendulum 47 cm long (a) on the Earth, and ( b) when it is in a freely falling elevator?

Liula [17]

Answer:

a)1.37 s

b)∞ ( Infinite)

Explanation:

Given that

L= 47 cm ( 1 m =100 cm)

L= 0.47 m

a)

On the earth :

Acceleration due to gravity = g

We know that time period of the simple pendulum given as

$T=2\pi\sqrt{ \dfrac{L}{g_{{eff}}}$

Here

$g_{eff}= g$

Now by putting the values

$T=2\pi \times\sqrt{ \dfrac{0.47}{9.81}}$

T=1.37 s

b)

Free falling elevator :

When elevator is falling freely then

$g_{eff}= 0$ ( This is case of weightless motion)

Therefore

$T=2\pi\sqrt{ \dfrac{L}{0}$

T=∞ (Infinite)

6 0

3 years ago

A photon of wavelength 192 nm strikes an aluminum surface along a line perpendicular to the surface and releases a photoelectron

alex41 [277]

Answer:

$KE=3.529\times10^{−27}\ J$

Explanation:

Given that

Wavelength λ=192 nm

So energy of photon,E

$E=\dfrac{hC}{\lambda }$

Now by putting the values

$h=6.6\times 10^{-34}\ m^2.kg/s$

$C=3\times 10^{8}\ m/s$

$E=\dfrac{6.6\times 10^{-34}\times 3\times 10^{8}}{192\times 10^{-9} }$

$E=1.03\times 10^{-18} J$

We know that

Kinetic energy given as

$KE=\dfrac{P^2}{2m}$

$KE=\dfrac{E^2}{2mC^2}$

$KE=\dfrac{(1.03\times 10^{-18})^2}{2\times 1.67\times 10^{-27}(3\times 10^8)^2}$

$KE=3.529\times10^{−27}\ J$

5 0

3 years ago

Alice and Marge are studying the properties of matter. The girls placed some an iron nail in a beaker containing water. Iron is

tatuchka [14]

Answer:

When substances made of iron are exposed to oxygen and moisture (water), rusting takes place. Rusting removes a layer of material from the surface and makes the substance weak. Rusting is a chemical change.

7 0

3 years ago

The sun the moon and the stars appear to move from east to west across the sky because earth rotates from blank to blank

mafiozo [28]

Answer: east and west

Explanation:The east

to west daily motions of stars, planets, the Moon, and the Sun are caused by the rotation of the Earth on its axis. The Earth and all the planets revolve around the Sun on circular orbits.

7 0

3 years ago