Answers:
a) -2.54 m/s
b) -2351.25 J
Explanation:
This problem can be solved by the <u>Conservation of Momentum principle</u>, which establishes that the initial momentum
must be equal to the final momentum
:
(1)
Where:
(2)
(3)
is the mass of the first football player
is the velocity of the first football player (to the south)
is the mass of the second football player
is the velocity of the second football player (to the north)
is the final velocity of both football players
With this in mind, let's begin with the answers:
a) Velocity of the players just after the tackle
Substituting (2) and (3) in (1):
(4)
Isolating
:
(5)
(6)
(7) The negative sign indicates the direction of the final velocity, to the south
b) Decrease in kinetic energy of the 110kg player
The change in Kinetic energy
is defined as:
(8)
Simplifying:
(9)
(10)
Finally:
(10) Where the minus sign indicates the player's kinetic energy has decreased due to the perfectly inelastic collision
Answer:
Selenium is a semiconductor
Explanation:
Selenium is a semiconductor.
Elements in the column IV and VI of the periodic table are referred to as Semiconductor.
Selenium lies in the column VI along with Tellurium
Some other elements of the column IV are silicon, germanium, and tin
Answer:
A police radar gun uses X-band microwave radiation at a frequency of 13.1 GHz. Microwaves travel at the speed of light, or 3x108 m/s. Since the frequency shift will be small for practical car speeds and difficult to detect, the shifted frequency is compared to the original frequency, and the resulting beat frequency is used to determine the speed of the car.
a.) If Michael is traveling at 29 m/s, what is the resulting beat frequency that the radar gun detects?
ANSWER: 2533 Hz
Explanation:
For radio broadcasting, in electricity meters, in any generator.
Answer:

Explanation:
First of all, we need to calculate the total energy supplied to the calorimeter.
We know that:
V = 3.6 V is the voltage applied
I = 2.6 A is the current
So, the power delivered is

Then, this power is delivered for a time of
t = 350 s
Therefore, the energy supplied is

Finally, the change in temperature of an object is related to the energy supplied by

where in this problem:
E = 3276 J is the energy supplied
C is the heat capacity of the object
is the change in temperature
Solving for C, we find:
