Question

You push a book across a table with a constant force, causing the book to accelerate. If you apply the same force to a stack of two identical books (twice the mass as the first case), the acceleration Group of answer choices will increase by a factor of four. will drop to 1/4 the original acceleration. will be cut by one half. stay the same. will double.

A wine glass fall to the floor and experiences a force of impact from the floor of 20N. The force the floor experiences from the glass is

Group of answer choices

effectively zero.

inversely proportional to the mass of the wine glass.

equal.

double that the glass experiences.

It takes 120 N to push a crate across the floor at constant speed. Which of the following conditions must be true (select ALL correct answers):

Group of answer choices

the crate is in dynamic equlibrium

the force of friction is -120 N

the net force is 120 N

the net force is zero

the crate will slowly speed up

the crate is in static equilibrium

the force of friction is zero

9.-You drop a ball off a cliff. Assume the acceleration due to gravity (g) is 10 m/s² and there is no air resistance. Find the _____and the total____ the fall falls after 4 seconds. Don't forget to include units with your answer, like: 90 m/s or 60 m.

10-√

Which of the following is true for an object in free-fall (ignoring air resistance):

Group of answer choices

the distance it falls every second increases every second

it's speed increases by about 10 m/s every second.

it falls a distance of 10 m every second

it's speed increases until it reaches 10 m/s, then it remains constant

11-

When a falling object experiences air resistance, it will eventually reach terminal velocity and no longer accelerate. This will happen when the force of air resistance

Group of answer choices

is less than the force of gravity acting on the object.

is equal to the object's weight.

is greater than the force of gravity acting on the object.

approaches zero.

Answer 1

1. From Newton's second law, Force = mass*acceleration or F = m*a ................(equation 1)

Let m be the mass of one book where force F was applied.

It is given that same force is applied for two books having twice the mass of one book. Therefore new mass would be 2*m.

Let new acceleration be a' .

F = 2*m*a' .......................................(equation 2)

Dividing equation 1 by equation 2, we obtain,

Therefore, correct answer is acceleration will be cut off by one half.

Accelration  will increase by a factor of four is not correct as there is no square term in the equation of F = ma.

Acceleration will drop to 1/4 the original acceleration is incorrect as there is no quadratic term in equation F =ma. Acceleration will stay the same is incorrect as for same amount of force the mass has doubled in second case.

Acceleration will double is incorrect because if the force remains same, mass is twice the original mass, to balance the constant force acceleration should decrease.