Answer:
(a) The announcer's claim is incorrect because the divers enter at a speed of 20.4 and not 25 m/s as announced
(b) it’s possible for a diver to enter the water with the velocity of 25 m/s if he has initial velocity of 14.4 m/s. The upward initial velocity can’t be physically attained
Explanation:
(a)
To find the final velocity
for an object traveling distance h taking the initial vertical component of velocity as
the kinematics equation is written as
where a is acceleration
Substituting g for a where g is gravitational force value taken as 9.81

Since the initial velocity is zero, we can solve for final velocity by substituting figures, note that 70 ft is 21.3 m for h
= 20.44275
Therefore, the divers enter with a speed of 20.4 m/s
The announcer's claim is incorrect because the divers enter at a speed of 20.4 and not 25 m/s as announced
(b)
The divers can enter water with a velocity of 25 m/s only if they have some initial velocity. Using the kinematic equation

Since we have final velocity of 25 m/s


= 14.390761 m/s
Therefore, it’s possible for a diver to enter the water with the velocity of 25 m/5 if he has initial velocity of 14.4 m/s
In conclusion, the upward initial velocity can’t be physically attained
The one at the base would be much older due to the law of super position, and the rock at the top would be much newer,again, due to the law of super position.
Answer:
a) True. The image of the mite is virtual
e) True. The image must be within the focal length of the eyepiece len
Explanation:
Let's review the general characteristics of compound microscopes
Formed by two converging lenses
Magnification is
M = -L/fo 0.25/fe
Where fo is the focal length of the objective lens and fe is the focal length of the ocular lens, L is the tube length
Let's review the claims
a) True. The image of the mite is virtual
b) False. The effect is the opposite of the magnification equation
c) False. The objective lens forms a real image
d) False. As the seal distance increases the magnification decreases
e) True. The image must be within the focal length of the eyepiece len
Answer:
2.46 eV
Explanation:
It is given that,
The energy of light that fall on the metal = 3.56 eV
The stopping potential of the metal = 1.1 V
We need to find the work function of the metal. It is given by the relation as follows :
W = E-KE ...(1)
Where KE is the kinetic energy of the ejected electron and it is given by :
KE = V×e
= 1.1 eV
Put all the values in formula (1)
W = 3.56 eV - 1.1 eV
= 2.46 eV
Hence, the work function of the metal is 2.46 eV. Hence, the correct option is (c).