Answer:
4 Ohms
Explanation
(This is seriously not as hard as it looks :)
You only need two types of calculations:
- replace two resistances, say, R1 and R2, connected in a series by a single one R. In this case the new R is a sum of the two:
- replace two resistances that are connected in parallel. In that case:
I am attaching a drawing showing the process of stepwise replacement of two resistances at a time (am using rectangles to represent a resistance). The left-most image shows the starting point, just a little bit "warped" to see it better. The two resistances (6 Ohm next to each other) are in parallel and are replaced by a single resistance (3 Ohm, see formula above) in the top middle image. Next, the two resistances (9 and 3 Ohm) are nicely in series, so they can be replaced by their sum, which is what happened going to the top right image. Finally we have two resistances in parallel and they can be replaced by a single, final, resistance as shown in the bottom right image. That (4 Ohms) is the <em>equivalent resistance</em> of the original circuit.
Using these two transformations you will be able to solve step by step any problem like this, no matter how complex.
Answer: Speed
Explanation:
Speed is the time it takes something to travel a certain distance. Accelaration is the rate at which an object's speed changes. Velocity is a vector of the object's speed and direction.
Answer:
+5300 kg m/s
Explanation:
In any type of collision, the total momentum is conserved. Therefore, we can just calculate the total momentum before the collision, and the final momentum will be equal to the initial one.
The total momentum before the collision is:
where
is the mass of the bus
is the mass of the car
is the initial velocity of the bus
is the initial velocity of the car
Substituting the numbers, we find
And since the total momentum is conserved, this is also the final momentum after the collision.
Answer:
The torque must be supplied by the motor to keep the wheel rotating at a constant angular velocity is 12 N-m.
Explanation:
Given that,
The coefficient of kinetic friction with the wheel is 0.60
Force acting against the wheel, F = 40 N
Let the distance is, r = 0.5 m
Torque is given by the product of force and distance. Here, the force will be :
Torque is given by :
So, the torque must be supplied by the motor to keep the wheel rotating at a constant angular velocity is 12 N-m.
The question is not complete so i have attached it.
Answer:
The light source is 2 cm from the bottom of the lamp
Explanation:
From the attached image, we can see that the parabola opens up with its vertex at the origin.
Now, the standard form of equation for a parabola is:
x² = 4ay
Looking at the parabola in the attachment, the top right edge of the lamp has a coordinate of (12,18)
Thus, we have;
12² = 4a(18)
144 = 72a
a = 144/72
a = 2
Looking at the parabola again, the line of symmetry is at x = 0
Thus, axis of symmetry is at x = 0.
Thus, focus is at (0, 2)
So, if the light source is placed at the focus, the distance of the light source from the bottom of the lamp is 2 cm
