Question

physics 7 unit 4 newtons laws 1 & 2
name_luis escolar_date 16/6/95 grade & element 4p4

1. what will happen to an object with no forces acting on it?
2. what will happen to a soccer ball when an external unbalanced force is applied to it?
3. if you are riding on a bus, what will happen to you when the driver hits the brakes suddenly when the bus is moving forward?
4. what unbalanced force causes a moving soccer ball to stop?
5. define inertia.
6. what happens to the acceleration of an object as its mass decreases if the net force remains the same?
7. what happens to the acceleration of an object if the net force on the object increases?
8. why would a grocery cart start moving faster if you gave it a hard push than if you gave it a soft push?
9. in what direction do objects accelerate?
10. why is a golf ball easier to accelerate than a bowling ball?
11. what is the formula for acceleration according to newtons 2nd law of motion?
12. define mass and discuss how it relates to inertia.
13. define newton’s first law of motion. what is another name for it?

Explanation:

1. According to Newton's first law, an object at rest stays at rest and an object in motion stays in motion with the same speed and in the same direction if no forces act on it.
2. An external un - balanced force will change the state of motion of the soccer ball, causing it to accelerate.
3. Due to inertia, when the bus brakes suddenly while moving forward, you will continue moving forward and lurch forward.
4. Friction is the unbalanced force that causes a moving soccer ball to stop.
5. Inertia is the tendency of an object to resist changes in its state of motion.
6. According to Newton's second law $F = ma$ (where $F$ is net force, $m$ is mass and $a$ is acceleration), if $F$ is constant and $m$ decreases, $a$ increases.
7. From $F = ma$, if the net force $F$ on an object increases, its acceleration $a$ increases.
8. A hard push applies a greater force. According to $F = ma$, a greater force results in a greater acceleration, so the grocery cart moves faster.
9. Objects accelerate in the direction of the net force acting on them.
10. A golf ball has less mass than a bowling ball. According to $F = ma$, for the same force, a smaller - mass object (golf ball) has a greater acceleration.
11. The formula for acceleration according to Newton's 2nd law of motion is $a=\frac{F}{m}$, where $a$ is acceleration, $F$ is the net force and $m$ is the mass of the object.
12. Mass is a measure of the amount of matter in an object. Inertia is directly related to mass; the greater the mass of an object, the greater its inertia, and it is more resistant to changes in motion.
13. Newton's first law of motion states that an object at rest stays at rest and an object in motion stays in motion with the same speed and in the same direction unless acted upon by an unbalanced force. It is also called the law of inertia.

Answer:

1. An object at rest stays at rest and an object in motion stays in motion with the same speed and in the same direction.
2. It will accelerate.
3. You will lurch forward.
4. Friction.
5. The tendency of an object to resist changes in its state of motion.
6. The acceleration increases.
7. The acceleration increases.
8. A hard push applies a greater force resulting in a greater acceleration.
9. In the direction of the net force.
10. A golf ball has less mass, so for the same force it has a greater acceleration.
11. $a = \frac{F}{m}$
12. Mass is a measure of the amount of matter. Greater mass means greater inertia.
13. An object at rest stays at rest and an object in motion stays in motion with the same speed and in the same direction unless acted upon by an unbalanced force. It is also called the law of inertia.