Answer:
D) 11 m/s
Explanation:
We have to calculate the velocity of the hot dog with respect to the observer still outside the train. This velocity will be given by:
where
is the velocity of the train (towards right)
is the velocity of the man (towards right)
is the velocity of the hot-dog (towards left, so we put a negative sign)
By replacing the numbers into the equation, we find
and the positive sign means the velocity is toward right.
Answer:
The density of the block is 7.4g/ml.
Explanation:
We can determine the volume of the metal block by taking the difference between the volumes measured in the graduated cylinder:
Now, as we know that the average density of an object is calculated dividing its mass by its volume, we can calculate the density ρ of the metal block using the expression:
Finally, it means that the density of the metal block is 7.4g/ml.
The average force is -212.4 N
Explanation:
We can solve this problem by using the impulse theorem, which states that the impulse exerted on the object (the product of the force exerted and the time) is equal to the change in momentum of the object:
where
F is the net force on the object
is the time
m is the mass
is the change in velocity
In this problem, we have:
m = 26.3 kg
Solving for F, we find
where the negative sign indicates that the direction of the force is opposite to the motion of the object.
Learn more about force and momentum:
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