Answer:
p = 4000 kg-m/s
Explanation:
Given that,
The mass of a truck, m = 200 kg
Speed of the truck, v = 20 m/s
We need to find the momentum of the truck. The formula for momentum is given by :
p = mv
so,
So, the momentum of the truck is equal to 4000 kg-m/s.
The astronaut will move at 0.4 m/s in the opposite direction to the wrench
Explanation:
We can solve this problem by using the law of conservation of momentum. In fact, the total momentum of the astronaut-wrench system must be conserved before and after the launch.
Before the launch, the total momentum is zero, since the astronaut is at rest:
p = 0 (1)
After the launch, the total momentum is:
(2)
where :
m = 2 kg is the mass of the wrench
v = 10 m/s is the velocity of the wrench
M = 50 kg is the mass of the astronaut
V is the recoil velocity of the astronaut
Since momentum is conserved, we can write (1) = (2), and so we can solve for V:
And the negative sign means that the astronaut will move in the opposite direction to the wrench.
Learn more about conservation of momentum:
#LearnwithBrainly
Answer:
4 Ohms
Explanation
(This is seriously not as hard as it looks :)
You only need two types of calculations:
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.
