Answer:
a) 4 289.8 J
b) 4 289.8 J
c) 6 620.1 N
d) 411 186.3 m/s^2
e) 6 620.1 N
Explanation:
Hi:
a)
The kinetic energy of the bullet is given by the following formula:
K = (1/2) m * v^2
With
m = 16.1 g = 1.61 x 10^-2 kg
v = 730 m/s
K = 4 289.8 J
b)
the work-kinetic energy theorem states that the work done on a system is the same as the differnce in kinetic energy of the same. Since the initial state of the bullet was at zero velocity (it was at rest) Ki = 0, therefore:
W = ΔK = Kf - Ki = 4 289.8 J
c)
The work done by a force is given by the line intergarl of the force along the trayectory of the system (in this case the bullet).
If we consider a constant force (and average net force) directed along the trayectory of the bullet, the work and the force will be realted by:
W = F * L
Where F is the net force and L is the length of the barrel, that is:
F = (4 289.8 J) / (64.8 cm) = (4 289.8 Nm) / (0.648 m) = 6620.1 N
d)
The acceleration can be found dividing the force by the mass:
a = F/m = (6620.1 N) /(16.1 g) = 411 186.3 m/s^2
e)
The force will have a magnitude equal to c) and direction along the barrel towards the exit
Answer:

Explanation:
<u>Net Force</u>
The Second Newton's law states that an object acquires acceleration when an external unbalanced net force is applied to it.
That acceleration is proportional to the net force and inversely proportional to the mass of the object.
It can be expressed with the formula:

Where
Fn = Net force
m = mass
The m=200 kg crate is pushed horizontally with a force Fa=700 N. The friction force opposes motion and a horizontal net force appears causing the acceleration.
The forces on the vertical direction are in balance since the crate does not accelerate in that direction, thus the weight and the normal force are equal:
N = W = mg
The friction force can be calculated by using the coefficient of friction μ:

Calculating the normal force:
N = 200 * 9.8 = 1,960 N
The friction force is:


The horizontal net force is:


Finally, the acceleration is computed:


Explanation:
the unit of area is called a derived unit because it is made of two fundamental unit metre and metre.
Answer: because of the magnetic
Explanation: If you hold a compass near a wire through which current is flowing, the needle on the compass will be deflected. Since compasses work by pointing along magnetic field lines, this means that there must be a magnetic field near the wire through which the current is flowing.
Answer:
2400 calories
Explanation:
given,
diameter of pizza,d₁ = 6 inches
calories of the 6 inches pizza = 600 calories
diameter of large size of pizza, d₂ = 12 inches
calories of the 12 inches pizza = ?
Area of the 6 inches pizza
A₁ = π x 3² = 9 π
Area of the 12 inches pizza
A₂ = π x 6² = 36 π
Ratio of 12 inch pizza to 6 inches
=
=
calories of the pizza

x = 2400 calories
Pizza of 12 inches is of calories is equal to 2400 calories