Answer:
<em>K =400000 J</em>
Explanation:
<u>Kinetic Energy</u>
Is the energy an object has due to its state of motion. It's proportional to the square of the speed.
The equation for the kinetic energy is:
Where:
m = mass of the object
v = speed at which the object moves
The kinetic energy is expressed in Joules (J)
The car has a mass of m=2000 Kg and travels at v=20 m/s. Calculating the kinetic energy:
Calculating:
K =400000 J
Answer:B
Explanation:
Initial velocity, u=0m/s
Distance,s=20m
a=+g=9.8m/s*s
Using v*v=u*u+2gs
v*v=0+2*9.8*20
v*v=392
v=19.8
When s=20m, v = 19.8m/s
Therefore when v = 10m/s, s= 10*20/19.8
s =10.1m
Answer: A negatively-charged ion always has more electrons than protons
Explanation:
First, we know that the elementary negative charge is the electron, while the positive one is the proton. Such that both have the same charge in magnitude, but a different sign. Such that if we have the same number of electrons and protons in an atom, the charge of this atom will be neutral.
And an ion is an atom with a different number of electrons and protons, so the charge of the atom is not neutral.
Then if we have a negatively-charged ion, the charge of this atom is negative. Then we must have a larger number of electrons (the negative ones) than protons (the positive ones)
Then the correct option is:
A negatively-charged ion always has more electrons than protons
Answer:
Explanation:
We shall represent displacement in vector form .Consider east as x axes and north as Y axes west as - ve x axes and south as - ve Y axes . 255 km can be represented by the following vector
D₁ = - 255 cos 49 i + 255 sin49 j
= - 167.29 i + 192.45 j
Let D₂ be the further displacement which lands him 125 km east . So the resultant displacement is
D = 125 i
So
D₁ + D₂ = D
- 167.29 i + 192.45 j + D₂ = 125 i
D₂ = 125 i + 167.29 i - 192.45 j
= 292.29 i - 192.45 j
Angle of D₂ with x axes θ
tan θ = -192.45 / 292.29
= - 0.658
θ = 33.33 south of east
Magnitude of D₂
D₂² = ( 192.45)² + ( 292.29)²
D₂ = 350 km approx
Tan
Answer:
EXplained
Explanation:
from conservation of energy
change in potential energy = gain in kinetic energy
so as all he balls are throws from the same height thus the change in potential energy is the same for all the balls thus the gain in kinetic energy is the same for all the balls and as they have the same initial velocity thus the final velocity is the same for all the balls.
