The correct answer is D. Becquerel showed that uranium gave off radioactivity, and the Curies discovered other radioactive elements.
D.all of the above is the answer for this question
Answer:

Explanation:
Given that,
Heat required, Q = 1200 J
Mass of the object, m = 20 kg
The increase in temperature, 
We need to find the specific heat of the object. The heat required to raise the temperature is given by :

So, the specific heat of the object is
.
M/s^2 is the correct answer
Answer:
d = V/E
Explanation:
From the definition, we can say that the electric field strength between the plates of a parallel plate capacitor is
E = v/d
where
E = electric field strength
V = potential difference
d = distance between the plates
On rearranging the equation and making d subject of the formula, we have
d = V/E
From the question, we're given that
V = 112 V
E = 1.12 kV/cm converting to V/m, we have 110000 V/cm
d = 112 / 110000
d = 0.00102 m
d = 1.02*10^-3 m