Answer:
we have to measure distances and time, possibly with an automated system since the values are very small
Explanation:
For this exercise we can use the relationship between momentum and momentum
I = ∫ F dt = Δp
F t = m
- mv₀
In the exercise they indicate that the final speed is zero
F t = - m v₀
F = -m v₀ / t
With this equation we can find what measurements should be carried out.
To find the speed with which the car collides with the wall, less measure the displacement and its time during the braking process before reaching the wall and from here find the speed with which it reaches the wall.
During the impact, we must find the time that the vehicle is in contact with the wall in the first approach is equal to the time that the car takes to reach the final speed of zero.
In summary we have to measure distances and time, possibly with an automated system since the values are very small
Answer:
4 m/s south
Explanation:
This is a pretty easy one.
Assume that the car has a reference point ragged x
We also know that the car starts moving at a point 10 m North of X. It moves steadily at a uniform velocity and ended at a position 10 m south of X.
If x is the reference point, we can infer that the car moves a total distance of, 10 m + 10 m.
Thus, the total distance moved by the car is 20 m.
It is also stated that it achieves that distance in 5 seconds.
Velocity is defined as the ratio of distance with respect to the tome taken, i.e V = d/t
Then, the velocity is
V = 20 / 5 = 4 m/s
Considering the fact that the car left and moved towards the south. We can say that it moved 4 m/s South.
The cooling find are there to keep the temperature low. They are mostly black in color, and hence, radiate heat, which is how the temperature is controlled.
Ok, assuming "mj" in the question is Megajoules MJ) you need a total amount of rotational kinetic energy in the fly wheel at the beginning of the trip that equals
(2.4e6 J/km)x(300 km)=7.2e8 J
The expression for rotational kinetic energy is
E = (1/2)Iω²
where I is the moment of inertia of the fly wheel and ω is the angular velocity.
So this comes down to finding the value of I that gives the required energy. We know the mass is 101kg. The formula for a solid cylinder's moment of inertia is
I = (1/2)mR²
We want (1/2)Iω² = 7.2e8 J and we know ω is limited to 470 revs/sec. However, ω must be in radians per second so multiply it by 2π to get
ω = 2953.1 rad/s
Now let's use this to solve the energy equation, E = (1/2)Iω², for I:
I = 2(7.2e8 J)/(2953.1 rad/s)² = 165.12 kg·m²
Now find the radius R,
165.12 kg·m² = (1/2)(101)R²,
√(2·165/101) = 1.807m
R = 1.807m