Answer:
the force of attraction between the two charges is 4.2 x 10⁹ N.
Explanation:
Given;
the magnitude of first charge, q₁ = 0.06 C
the magnitude of the second charge, q₂ = 0.07 C
distance between the two charges, r = 3 m
The force of attraction between the two charges is calculated as ;

where;
k is Coulomb's constant = 9 x 10⁹ Nm²/C²

Therefore, the force of attraction between the two charges is 4.2 x 10⁹ N.
Answer:
(a)

(b)
1120 N
Explanation:
Change in velocity,
is given by subtracting the initial velocity from the final velocity and expressed as 
Where v represent the velocity and subscripts f and i represent final and initial respectively. Since the ball finally comes to rest, its final velocity is zero. Substituting 0 for final velocity and the given figure of 8 m/s for initial velocity then the change in velocity is given by

To find
then we substitute 7 kg for m and -8 m/s for
therefore 
(b)
The impact force, F is given as the product of mass and acceleration. Here, acceleration is given by dividing the change in velocity by time ie

Substituting t with 0.05 s then 
Since F=ma then substituting m with 7 Kg we get that F=7*-160=-1120 N
Therefore, the impact force is equivalent to 1120 N
Answer:
OPTION A, Kelvin Thermometer is Incorrect
Explanation:
Now, if you consider best two out of three results, then celsius and Fahrenheit thermometers read the same value, meaning both are right.
1) K = °C + 273
K = 100°C + 273
k = 373°C
Kelvin Thermometer is Incorrect
2) 
when we have 212°F

which is correct
Answer:
The convex lens is shaped so that all light rays that enter it parallel to its axis cross one another at a single point on the opposite side of the lens.
Explanation:
Answer:
.00135 j
Explanation:
K.E. = 1/2 m v^2
= 1/2 * .03 * .3^2 = .00135 j