Answer:
The negative electrode of a battery has an excess of positive charge
Explanation:
This is because in every battery, there is a negative electrode ( cathode ) and only positive charge is deposited on it.
For other statements:
Batteries donot store electric charge but they store chemical energy
Some batteries donot use metals for the flow of electrons, but some use hydrogen gas at a pressure of 1 atmosphere.
Answer:
t=0.42s
Explanation:
Here you have an inelastic collision. By the conservation of the momentum you have:

m1: mass of the bullet
m2: wooden block mass
v1: velocity of the bullet
v2: velocity of the wooden block
v: velocity of bullet and wooden block after the collision.
By noticing that after the collision, both objects reach the same height from where the wooden block was dropped, you can assume that v is equal to the negative of v2. In other words:

Where you assumed that the negative direction is upward. By replacing and doing v2 the subject of the formula you get:

Now, with this information you can use the equation for the final speed of an accelerated motion and doing t the subject of the formula. IN other words:

hence, the time is t=0.42 s
Answer:
1.11 V
Explanation:
Given that the Einstein photoelectric equation states that;
KE = E - Wo
E = energy of incident photon
Wo= work function of the metal
E = hf = 6.64 x 10-34 * 6 x 1014
E = 39.84 * 10^-20 J or 3.98 * 10^-19 J
KE = 3.98 * 10^-19 J - 2.2 x 10-19J
KE = 1.78 * 10^-19J
We convert this value of KE to electron volts
KE = 1.78 * 10^-19J/1.6 x 10-19C
KE = 1.11 eV
Hence; 1.11 V will be just sufficient to stop electrons emitted by the sodium photo-plate reaching the collector plate.
Answer: 330.88 J
Explanation:
Given
Linear velocity of the ball, v = 17.1 m/s
Distance from the joint, d = 0.47 m
Moment of inertia, I = 0.5 kgm²
The rotational kinetic energy, KE(rot) of an object is given by
KE(rot) = 1/2Iw²
Also, the angular velocity is given
w = v/r
Firstly, we calculate the angular velocity. Since it's needed in calculating the Kinetic Energy
w = v/r
w = 17.1 / 0.47
w = 36.38 rad/s
Now, substituting the value of w, with the already given value of I in the equation, we have
KE(rot) = 1/2Iw²
KE(rot) = 1/2 * 0.5 * 36.38²
KE(rot) = 0.25 * 1323.5
KE(rot) = 330.88 J