Answer:
-2000 N
Explanation:
First of all, let's calculate the acceleration of the car:
where
v = 0 is the final velocity of the car
u = 10 m/s is the initial velocity of the car
t = 5 s is the time elapsed
Substituting,
where the negative sign means it is a deceleration.
Now we can calculate the average braking force:
where m=1000 kg is the mass of the car. Substituting,
and the negative sign means the force is opposite to the direction of motion of the car.
Answer:
The current halves
Explanation:
The relationship between voltage, current and resistance in a circuit is given by Ohm's law:
where
V is the voltage
R is the resistance
I is the current
We can rewrite the formula as
we see that I is directly proportional to V and inversely proportional to R. In this problem, V is held constant while R is doubled:
so, the new current in the circuit will be
So, the current halves.
The beginning momentum of the object is zero
Explanation:
The momentum of an object is given by:
where
m is the mass of the object
v is its velocity
For the object in this problem, we have:
m = 3.0 kg is its mass
v = 0, because it is initially at rest, so its initial velocity is zero
Therefore, the initial momentum of the object is
Learn more about momentum:
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