The amount of heat needed to increase the temperature of a substance by

is given by

where m is the mass of the substance, Cs is its specific heat capacity and

is the increase of temperature.
If we re-arrange the formula, we get

And if we plug the data of the problem into the equation, we can find the specific heat capacity of the substance:
Answer:
i. The error is the rough convex mirror.
ii. This should be replaced with a smooth convex morror.
Explanation:
Reflection is dependent on the surface involved and has two types; diffuse and specular. When the surface is rough, diffused reflection is observed. The surface causes a distortion of the incident light (the rays would be reflected at different angles to one another) after reflection. This makes some rays to interfere with one another. While specular reflection is observed with a smooth surface.
In the statement, the rough convex mirror would produce a distorted reflection which would produce diffused reflection. The effect is that few or no rays (depending on the degree of how rough the surfce is) would be reflected to the other smooth, flat diagonal mirror.
What’s the question or problem ?
given:
mass = 5000 kg
u (initial velocity) = 0 m/s
v (final velocity) = 70 m/s
time taken to change velocity = 3600 s
acceleration = v - u / t
a = 70 - 0 / 3600
a = 70 / 3600
a = 0.0194 m/s2 (approx)
given: mass = 5000 kg
acceleration = 0.0194 (found in 1st part)
force = mass * acceleration
f = ma
f = 5000*0.0194 = 97 N
therefore the acceleration will be 0.0194 m/s2
and the force involved in acceleration will be 97 N
An element called Silica.