Answer:
288N
Explanation:
Given parameters:
Mass of Cheetah = 12kg
Acceleration = 24m/s²
Unknown:
Force needed by the cheetah to run = ?
Solution:
The force needed by the Cheetah to run is the net force.
According to Newton's law;
Force = mass x acceleration
Insert the given parameters and solve;
Force = 12 x 24 = 288N
<h3><u>Answer;</u></h3>
Large mirrors are easier to build than large lenses.
<h3><u>Explanation;</u></h3>
- <em><u>Reflector telescopes have a number of advantages as compared to refracting telescopes and other types of telescopes. </u></em>
- <em><u>Reflector telescopes do not suffer from chromatic aberration because all wavelengths will reflect off the mirror in the same way. The support for the objective mirror is all along the back side so they can be made very large.</u></em>
- Additionally, reflector telescopes are cheaper to make than refractors of the same size. Also since in reflector telescopes light is reflecting off the objective, rather than passing through it, only one side of the reflector telescope's objective needs to be perfect.
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.
To solve this exercise, it is necessary to apply the concepts of conservation of the moment especially in objects that experience an inelastic colposition.
They are expressed as,
Where,
= mass of the skier
= mass of the cat
= initial velocity of skier
= initial velocity of cat
= final velocity of both
Re-arrange to find V_f we have,
Once the final velocity is found it is possible to calculate the change in kinetic energy, so
Therefore the amount of kinetic energy converted in to internal energy is 819J
Friend #1 gets at least 2/5 of a pizza.
Friend #2 gets at least 2/5 .
Friend #3 gets at least 2/5 .
Friend #4 gets at least 2/5 .
Friend #5 gets at least 2/5 .
Friend #6 gets at least 2/5 .
Sum . . . . . . . . . at least 12/5 of a pizza.
Simplify . . . . . . at least 2.4 pizzas.
-- If pizzas can be bought by the half, they should order at least <em>2-1/2 pizzas.</em>
-- If only whole pizzas have to be ordered, then they should order at least <em>3 pizzas.</em>
