Answer:
(a) t = 1.67 s
(b) s₂ = 45 m
Explanation:
Here, we use the formula:
s = vt
FOR Seth:
s₁ = v₁t₁
where,
s₁ = distance covered by Seth
v₁ = speed of Seth = 9 m/s
t₁ = time taken by Seth
FOR Mack:
s₂ = v₂t₂
where,
s₂ = distance covered by Mack
v₂ = speed of Mack = 27 m/s
t₂ = time taken by Mack
since, initially Mack is 30 m behind Seth. Therefore,
(a)
s₂ = s₁ + 30 m
using formulae:
v₂t₂ = v₁t₁ + 30 m
but, the time of catching is same for both (t₁ = t₂ = t)
v₂t = v₁t + 30 m
using values:
(27 m/s)t - (9 m/s)t = 30 m
t = (30 m)/(18 m/s)
<u>t = 1.67 s</u>
(b)
s₂ = v₂t
using values:
s₂ = (27 m/s)(1.67 s)
<u>s₂ = 45 m</u>
Hi there!
We can use the conservation of angular momentum to solve.
I = moment of inertia (kgm²)
ω = angular velocity (rad/sec)
Recall the following equations for the moment of inertia.
Begin by converting rev/sec to rad sec:
According to the above and the given information, we can write an equation and solve for ωf.
1.) Two positive charges of 4.3 mC each are separated by 0.25 m.
What is the size and type of force between the two charges? Help
2.) A positive charge of 1.32 x 10-4 C and a negative charge of 9.8 mC
are 0.015 m apart. What is the size and type of force between them? H
3.) Two electrons in an atom are separated by 1.5 x 10-10 m , the typical size
of an atom. What is the size and type of force between them? H
4.) A negative charge of 4.7 mC exerts a repulsive force of 51.0 N on a 2nd charge
0.062 m away. What is the size and polarity (pos or neg) of the 2nd charge? H
5.) A negative charge of 9.3 x 10-5 C exerts an attractive force of 37.4 N when
placed 0.080 m away from a 2nd charge. Find size and polarity of 2nd charge. H
6.) Two positive charges of 3.0 mC exert a repulsive force of 2.0 N on each other.
By what distance are they separated? H
7.) Two charges q1 and q2 are separated by a distance, d and exert a force, F1
on each other. What new force (F2) will exist if:
a) q1 is doubled. H d) d is doubled. H
b) q1 is doubled and q2 is tripled. H e) d is tripled. H
c) q1 is cut in half. H f) q2 is doubled and d is cut in half. H
8.) a) How many electrons are there in 1 C ? H
b) How many excess electrons are on a ball with a charge of -5.26 x 10-17 C ? H
c) How many excess protons are on a ball with a charge of 7.29 x 10-12 C ? H
9.) How many coulombs of negative charge does a 5 gram nickel coin have?
[takes 3 steps; do a) , b) and c) to get answer, don't round off until part c]
a) Find the number of atoms in a nickel.
Its mass is 5 g and nickel has 6.02 x 1023 atoms / 58 g. H
b) Find the number of electrons in the coin. There are 28 electrons / atom. H
c) Find how many coulombs of negative charge in a nickel. 1.6 x 10-19 C / 1 e- H
10.) A lightning bolt transfers 35 C to Earth. How many electrons are transferred? H
Answer:
When a man travels from Hilly region to Terai region, his weight gradually increases because the value of g is more at the Terai region than that in hilly region. 3. An object weights 20 N in air and 16 N in liquid, then answer the following questions.
Explanation:
because the value of g is more at the Terai region than that in hilly region. 3. An object weights 20 N in air and 16 N in liquid, then answer the following questions.
Missing part in the text of the problem:
"<span>Water is exposed to infrared radiation of wavelength 3.0×10^−6 m"</span>
First we can calculate the amount of energy needed to raise the temperature of the water, which is given by
where
m=1.8 g is the mass of the water
is the specific heat capacity of the water
is the increase in temperature.
Substituting the data, we find
We know that each photon carries an energy of
where h is the Planck constant and f the frequency of the photon. Using the wavelength, we can find the photon frequency:
So, the energy of a single photon of this frequency is
and the number of photons needed is the total energy needed divided by the energy of a single photon:
