Question

An object has a weight of 21,532 N on Earth. What is the mass of the object?

Question 7 options:

2,200 g


2,197 kg


215,000 kg


none of the above

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Question 8 (10 points) Question 8 Unsaved
What is the mass of the object from the previous question if we put it on the moon? The force of gravity on the moon is 1.62 m/s2

Question 8 options:

21,532 kg


2,197 N


3,515 N


2,197 kg

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Question 9 (10 points) Question 9 Unsaved
How much force is exerted if a 250 kg object has an acceleration of 750 m/s2 ?

Question 9 options:

0.33 N


187,500 N


3 N


none of the above

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Question 10 (10 points) Question 10 Unsaved
A resting soccer ball moving after it is kicked is an example of which of Newton's laws?

Question 10 options:

1st Law


2nd Law


3rd Law

Answer 1

7) 2,197 kg

The weight of an object on Earth is given by:

$W=mg$

where m is the mass of the object and $g=9.8 m/s^2$ is the acceleration due to gravity. Since we know the weight of the object, W=21,532 N, we can re-arrange the equation to calculate the object's mass:

$m=\frac{W}{g}=\frac{21,532 N}{9.8 m/s^2}=2,197 kg$

8) 2,197 kg

Mass is an intrinsec property of an object: it says "how much matter" is contained within an object. Therefore, the mass of an object does not depend on its location: so, the object has the same mass on Earth and on the moon, and so its mass is still the same as the previous exercise, 2,197 kg.

9) 187,500 N

The force exerted on an object is given by Newton's second law:

$F=ma$

where m is the mass of the object and a its acceleration. In this problem, $m=250 kg$ and $a=750 m/s^2$, so the force exerted on the object is

$F=(250 kg)(750 m/s^2)=187,500 N$

10) 2nd Law

Newton's second law states that an object which is acted upon a force experiences an acceleration given by:

$a=\frac{F}{m}$

where F is the force and m the mass of the object. As a result, the object accelerates, so if it was at rest, it starts moving.

This is exactly what happens in this example: the ball is initially at rest, but then a force is applied on it (by the kick), so the ball is accelerated and it starts moving.

Answer 2

Question number 7.

Answer:

The mass of the object will be 2197.14 kg, option B.

Explanation:

Given data:

The weight of the object = 21532 N

Mass of the object =?

Formula:

             w/F = mg

              m = F/g                                                ∴ g = 9.8 m/s2

Butting value in above formula:

             m = 21532/9.8

             m = 2197.14 kg

Hence an object having weight of 21532 on earth has mass of 2197.14 kg. It is near to the option b, so option b is the correct option.

Here g is the gravitational acceleration of the earth which is a constant value,9.8 m/s2.

Question number 8.

Answer:

The correct answer is option B which is 2197 kg.

Explanation:

The mass of the object will remain the same as it was on the earth. The reason is that mass of the object does not depend upon the gravity of the earth or moon. It is an intrinsic property of objects. Hence when an object is moved from earth to moon, its weight will change, not the mass.

Question No. 9

Answer:

The correct answer is option B which is 187,500 N.

Explanation:

Given:

Mass of the object = 250 kg

Acceleration of the object = 750 m/s2

Force/weight of object = ?

Solution:

Formula:

            F = mg

Putting values in formula:

            F = 250 * 750

             F = 187,500 N

Hence the force exerted on the object having mass of 250 kg and acceleration of 750 is equal to 187,500 N.

The question no. 10

Answer:

The correct answer is option A which is 1st Law.

Explanation:

In this statement, first, the ball is described as resting and then it moves after applying a force by kicking.

Newton's first law of motion states that an object in resting position or moving with a uniform velocity will not change its state, instead of applying a force.

Hence kicking is applying a force on the ball, which changes its state from resting to moving state.