Answer:
(A) Q = 321.1C (B) I = 42.8A
Explanation:
(a)Given I = 55A−(0.65A/s2)t²
I = dQ/dt
dQ = I×dt
To get an expression for Q we integrate with respect to t.
So Q = ∫I×dt =∫[55−(0.65)t²]dt
Q = [55t – 0.65/3×t³]
Q between t=0 and t= 7.5s
Q = [55×(7.5 – 0) – 0.65/3(7.5³– 0³)]
Q = 321.1C
(b) For a constant current I in the same time interval
I = Q/t = 321.1/7.5 = 42.8A.
Answer:
Magnetic energy and electromagnetic energy form of potential energy followed by a form of kinetic energy.
(B) is correct option.
Explanation:
Given that,
Lists a form of potential energy followed by a form of kinetic energy
We know that,
Sound energy :
The movement of energy through object it is called sound energy. When a object produced vibration by force then it moves in wave.
Sound wave is example of kinetic energy.
Nuclear energy :
The store energy in the nucleus of the atom it is called nuclear energy. This energy released when occurs fusion and fission.
Nuclear energy is the example of potential energy
Magnetic energy :
Magnetic energy is a type of potential energy which is depend on distance and position in the magnetic field.
Electromagnetic energy :
Electromagnetic energy is light energy. it is type of kinetic energy.
Gravitational energy :
Gravitational energy is a type of potential energy. It is an energy related with gravity or gravitational force.
Elastic energy :
The store energy in elastic object it is called elastic energy. This energy is a type of potential energy.
Electrical energy :
The movement of electrons is called electrical energy. When electrons move through a wire then it is are called electricity. Electrical energy is type of kinetic energy.
Hence, Magnetic energy and electromagnetic energy form of potential energy followed by a form of kinetic energy.
(B) is correct option.
B.absorb neutrons to prevent chain reactions which become uncontrollable
Answer:
The work done by the child as the tricycle travels down the incline is 416.96 J
Explanation:
Given;
initial velocity of the child, 
= 1.4 m/s
final velocity of the child, 
= 6.5 m/s
initial height of the inclined plane, h = 2.25 m
length of the inclined plane, L = 12.4 m
total mass, m = 48 kg
frictional force, 
= 41 N
The work done by the child is calculated as;
Therefore, the work done by the child as the tricycle travels down the incline is 416.96 J
Answer:
4.4 seconds
Explanation:
Given:
a = -5.5 m/s²
v₀ = 0 m/s
y₀ = 53 m
y = 0 m
Find: t
y = y₀ + v₀ t + ½ at²
0 = 53 + 0 + ½ (-5.5) t²
0 = 53 − 2.75 t²
t = 4.39
Rounded to two significant figures, it takes 4.4 seconds for the object to land.
