Answer: The chemical energy is converted to heat, light ,sound and kinematic movements.
Explanation:
An exploding firework is essentially a number of chemical reactions happening simultaneously or in rapid sequence. When you add some heat, you provide enough activation energy (the energy that kick-starts a chemical reaction) to make solid chemical compounds packed inside the firework combust (burn) with oxygen in the air and convert themselves into other chemicals, releasing smoke and exhaust gases such as carbon dioxide, carbon monoxide, and nitrogen in the process. For example, this is an example of one of the chemical reactions that might happen when the main gunpowder charge burn.
some of the chemical energylocked inside them is converted into four other kinds of energy (heat, light, sound, and the kinetic energy of movement). According to a basic law of physics called the conservation of energy.
Answer:
-352.275KJ
Explanation:
We are given that
Mass of car=1500kg
Initial speed of car =u=96 km/h=
1km/h=
Final speed of car=v=56km/h=
Distance traveled by car=s=55m
We have to find the work done by the car's braking system.
Using third equation of motion




Where negative sign indicates that velocity of car decreases.
Work done by a car's barking system=
Work done by a car's barking system=
Work done by a car's barking system=
1KJ=1000J
Where negative sign indicates that work done in opposite direction of motion.
Answer:
The percentage change in resistance of the wire is 69%.
Explanation:
Resistance of a wire can be determined by,
R = (ρl) ÷ A
Where R is its resistance, l is the length of the wire, A its cross sectional area and ρ its resistivity.
When the wire is stretched, its length and area changes but its volume and resistivity remains constant.
= 1.3l, and
= 
So that;
= (ρ
) ÷
= (ρ × 1.3l) ÷ (
)
= (1.3lρ) ÷ (
)
=
× [(ρl) ÷ A]
= 1.69R (∵ R = (ρl) ÷ A)
= 1.69R
Where
is the new resistance,
is the new length, and
is the new area after stretching the wire.
The change in resistance of the wire =
- R
= 1.69R - 1R
= 0.69R
The percentage change in resistance =
× 100
= 0.69 × 100
= 69%
The percentage change in resistance of the wire is 69%.