I believe the last one about the bike is correct.
Answer:
1703.24J
Explanation:
Given parameters:
Mass of brick = 7.9kg
Height of building = 22m
Unknown:
Potential energy of the brick = ?
Solution:
The potential energy of a body is the energy at rest of the body. Mathematically;
P.E = mgh
m is the mass of the brick
g is the acceleration due to gravity
h is the height of the building
Insert the given parameters and solve;
P.E = 7.9 x 9.8 x 22 = 1703.24J
Answer:
the longest wavelength of incident sunlight that can eject an electron from the platinum is 233 nm
Explanation:
Given data
Φ = 5.32 eV
to find out
the longest wavelength
solution
we know that
hf = k(maximum) +Ф ...............1
here we consider k(maximum ) will be zero because photon wavelength max when low photon energy
so hf = 0
and hc/ λ = +Ф
so λ = hc/Ф ................2
now put value hc = 1240 ev nm and Φ = 5.32 eV
so hc = 1240 / 5.32
hc = 233 nm
the longest wavelength of incident sunlight that can eject an electron from the platinum is 233 nm
Answer:
a planet
Explanation:
a planet is one which exerts these properties and therefore is the answer
Answer : 413.44N
Here it is given that an elevator is moving down with an acceleration of 3.36 m/s² . And we are interested in finding out the apparent weight of a 64.2 kg man . For the diagram refer to the attachment .
- From the elevator's frame ( non inertial frame of reference) , we would have to think of a pseudo force.
- The direction of this force is opposite to the direction of acceleration the frame and its magnitude is equal to the product of mass of the concerned body with the acceleration of the frame .
- When a elevator accelerates down , the weight recorded is less than the actual weight .
From the Free body diagram ,
- Mass of the man = 64.2 kg