Answer: 9.81m/s^2
Explanation: since it’s free fall and friction is neglected, the magnitude of the ball’s acceleration will be equal to the general acceleration due to gravity which is 9.81m/s^2
Answer:
Please refer to the figure.
q1 is a negative charge, and q2 and q3 are positive charges. So, the force exerted by q1 on q3 is attractive, and the force exerted by q2 on q3 is repulsive, which means F13 is directed towards left, and F23 is also directed towards left.


The net force on q3 is the sum of these two forces:

Since both forces are directed towards left, their sign should be negative.
Answer:

Explanation:
Given:
Initial mass of isotope (m₀) = 20 g
Half life of the isotope
= (ln 4) years
The general form for the radioactive decay of a radioactive isotope is given as:

Where,

So, the equation is: 
At half-life, the mass is reduced to half of the initial value.
So, at
. Plug in these values and solve for 'k'. This gives,

Hence, the equation for the mass remaining is given as:

charge needed= 169412 C
Explanation:
energy stored in the battery= 16 KWh= 16 (1000 W)(3600 s)= 5.76 x 10⁷ J
Energy stored is given by U= q V
q= charge
V= voltage= 340 V
so 5.76 x 10⁷ = q (340)
q= 169412 C