Answer:
t = 3.35 s
Explanation:
It is given that,
Mass of a pumpkin, m = 8 kg
It is dropped from a height of 55 m
We need to find the time taken by it to hit the ground.
Initial velocity of the pumpkin, u = 0
Using second equation of motion to find it as follows :
So, it will take 3.35 seconds to hit the ground.
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:
B The force that the floor of the elevator exerts on you and the force that you exert on the floor of the elevator
Explanation:
A. is incorrect because the force of gravity on you will always stays the same while the force of the elevator exerts on you changes as it takes you upward
B. is correct in accordance to Newton's 3rd law of action and reaction forces.
C. is incorrect because gravity force stays the same while the force that you exerts on the floor change as elevator moving upward.
D. is incorrect although it states Newton's 1st law. However there can still be pair of forces (part B) that could counter balance each other among other forces.
