<span>Volume of air in the balloon 1.01 x 10^6 L
Density of air is 1.20 g/l
Mass = Density X Volume
So mass of the air in the Balloon= ( 1.01 x 10^6) X 1.20 = 1.212 x 10^6 g
As the air is heated, the volume of air in the balloon expands to 1.10x 10^6 L
Density= Mass/ voume
So the Density of heated air = 1.212 x 10^6/ 1.10x 10^6 = 1.101 g/l
The answer is 1.101 g/l.</span>
B) a rock being tossed high into the air
Answer:
a) 378Ns
b) 477.27N
Explanation:
Impulse is the defined as the product of the applied force and time taken. This is expressed according to the formula
I = Ft = m(v-u)
m is the mass = 70kg
v is the final velocity = 5.4m/s
u is the initial velocity = 0m/s
Get the impulse
I = m(v-u)
I = 70(5.4-0)
I = 70(5.4)
I = 378Ns
b) Average total force is expressed as
F = ma (Newton's second law)
F = m(v-u)/t
F = 378/0.792
F = 477.27N
Hence the average total force experienced by a 70.0-kg passenger in the car during the time the car accelerates is 477.27N
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
The frictional force is directly proportional to the force that is perpendicular on the surface.
When the body is placed on a horizontal level with zero inclination, the only force acting on the body is the gravitational force which always pulls the body down. The gravitational force, in this case, is the perpendicular force to the surface. Accordingly, this entire force is used to generate friction
Now as the inclination of the surface increases, the gravitational force is no longer the perpendicular force of the body, its value decreases, which means only a part is used to generate frictional force. Consequently, frictional force decreases.
When the inclination reaches 90 degrees, the gravitational force does not act along the normal and accordingly, no friction force is generated.
