Melting, as igneous rock is magma or lava that has cooled and hardened.
Answer:
a) 
b) 
Explanation:
Given:
- upward acceleration of the helicopter,
- time after the takeoff after which the engine is shut off,
a)
<u>Maximum height reached by the helicopter:</u>
using the equation of motion,
where:
u = initial velocity of the helicopter = 0 (took-off from ground)
t = time of observation
b)
- time after which Austin Powers deploys parachute(time of free fall),
- acceleration after deploying the parachute,
<u>height fallen freely by Austin:</u>
where:
initial velocity of fall at the top = 0 (begins from the max height where the system is momentarily at rest)
time of free fall
<u>Velocity just before opening the parachute:</u>
<u>Time taken by the helicopter to fall:</u>
where:
initial velocity of the helicopter just before it begins falling freely = 0
time taken by the helicopter to fall on ground
height from where it falls = 250 m
now,
From the above time 7 seconds are taken for free fall and the remaining time to fall with parachute.
<u>remaining time,</u>
<u>Now the height fallen in the remaining time using parachute:</u>
<u>Now the height of Austin above the ground when the helicopter crashed on the ground:</u>
Downward movement under the force of gravity only.
Answer: a) 274.34 nm; b) 1.74 eV c) 1.74 V
Explanation: In order to solve this problem we have to consider the energy balance for the photoelectric effect on tungsten:
h*ν = Ek+W ; where h is the Planck constant, ek the kinetic energy of electrons and W the work funcion of the metal catode.
In order to calculate the cutoff wavelength we have to consider that Ek=0
in this case h*ν=W
(h*c)/λ=4.52 eV
λ= (h*c)/4.52 eV
λ= (1240 eV*nm)/(4.52 eV)=274.34 nm
From this h*ν = Ek+W; we can calculate the kinetic energy for a radiation wavelength of 198 nm
then we have
(h*c)/(λ)-W= Ek
Ek=(1240 eV*nm)/(198 nm)-4.52 eV=1.74 eV
Finally, if we want to stop these electrons we have to applied a stop potental equal to 1.74 V . At this potential the photo-current drop to zero. This potential is lower to the catode, so this acts to slow down the ejected electrons from the catode.
Answer:
the force of gravity between them is quadrupled .
Explanation:
Since gravitational force is inversely proportional to the square of the separation distance between the two interacting objects, more separation distance will result in weaker gravitational forces.
