<u>Answer</u>
a) properties and hazards
<u>Explanation</u>
Having information on properties of a chemical helps you know the reactivity of that chemicals.
Most chemicals are very reactive. So you have to be away of their hazards to avoid accidents.
Exactly the same way that you can photograph a mountain or a skyscraper
with the itty bitty camera in your smartphone.
Lenses are used to form a tiny image of a gigantic object.
Answer:
200 N
Explanation:
For a body moving in uniform circular motion, the force acting on it will be <em>centripetal force</em> and its direction is <em>radially inward</em> , pointing to the center.
The radially inward acceleration, or the centripetal acceleration is given by :
a = v² / r
where v is the speed at which the body is moving and r is the radius of the circle
Given-
m = 55kg
v = 14.1 m/s
r= 55m
We know that F = ma
⇒ F = m ( v²/ r )
⇒ F = 55 x 14.1 x 14.1 / 55
⇒ F =14.1 x 14.1 = 200 N
∴ <em>The force acting is 200 N</em>.
Answer: The increase in temperature of the nail after the three blows is 8.0636 Kelvins. The correct option is (d).
Explanation:
Kinetic energy of the hammer ,K.E.=

Half of the kinetic energy of the hammer is transformed into heat in the nail.
Energy transferred to the nail in one blow =

Total energy transferred after 3 blows,Q =
Mass of the nail = 15 g = 0.015 kg
Change in temperature =
Specif heat of the steel = c = 448 J/kg K



The increase in temperature of the nail after the three blows is 8.1 Kelvins.Hence, correct option is (d).
Answer:
C
Explanation:
Ray of light when hits any specimen or object. The light is partially reflected, partially reflected and partially absorbed. It is never completed reflected, refracted or absorbed. Hence, the correct answer would be c.