Why g value varies but G is constant
1 answer:
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Answer:
From lowest to highest acceleration:
3rd train
2nd train
1st train
Explanation:
The acceleration of an object can be found by using Newton's second law:
where
a is the acceleration
F is the net force on the object
m is the mass of the object
We notice that for equal values of the forces F, the acceleration a is inversely proportional to the mass, m. Therefore, greater mass means lower acceleration, and viceversa.
So, the train with lowest acceleration is the one with largest mass, i.e. the 3rd train consisting of 50 equally loaded freight cars. Then, the 2nd train has larger acceleration, since it consists of 50 empty freight cars (so its mass is smaller). Finally, the 1st train (a single empty car) is the one with largest acceleration, since it is the train with smallest mass.
Answer:
<em>The 150 lb woman at 30 mph would experience the greatest force of impact in a sudden collision.</em>
Explanation:
<u>Momentum </u>
The force of impact exerted on an moving object that suddenly stops or changes its movement is measures by the physics magnitude called Impulse, which can be computed with the formula
Where F is the force and t is the time that force acts to produce the impact on the object. The impulse is also defined as the change in the momentum of the object:
Or equivalently
The question describes four situations where different persons and object suffer impact that make them stop from their moving state. Thus and the impulse is
We are only interested in the relative magnitudes of each case, so we won't consider the sign in the calculations
Case 1: A 200 lb. man traveling 20 mph
Case 2: A 150 lb. woman at 30 mph
Case 3: A 35 lb. infant at 75 mph
Case 4: A 75 lb. child at 55 mph
By comparing the results, we can see that the 150 lb woman at 30 mph would experience the greatest force of impact in a sudden collision.