Question

Question 1 (10 points) The path a projectile takes is known as the Question 1 options: vertical component trajectory horizontal component parabola Question 2 (10 points) Which of the following is not an example of a projectile? Question 2 options: A baseball that has been pitched A rock being thrown over a bridge A person sitting in a chair, not moving A car driving off a cliff Question 3 (10 points) A plane is flying east when it drops some supplies to a designated target below. The supplies land after falling for 10 seconds. How high above the ground was the airplane when the supplies were dropped? (Hint: d = 1/2gt2; g = -9.8 m/s2) Question 3 options: 120 meters 490 meters 980 meters 49 meters Question 4 (10 points) As the supplies fell, they traveled 650 meters horizontally. How fast were the supplies and the airplane moving forward? Remember that it took 10 seconds for them to reach the ground. (Hint: v = d/t) Question 4 options: 65 m/s 6500 m/s 0.154 m/s 660 m/s Question 5 (10 points) A projectile has a vertical component and a horizontal component. Question 5 options: True False Question 6 (10 points) The shape of a projectile's trajectory is an ellipse. Question 6 options: True False Question 7 (10 points) Which of the following is not true about a vertical component? Question 7 options: The vertical component of a projectile changes due to gravity. The vertical component acts the same as an object in free fall. The vertical component always equals the horizontal component. Question 8 (10 points) During the course of trajectory, the horizontal component of the velocity is Question 8 options: constant increasing decreasing negative Question 9 (10 points) In the simulation above, as the projectile travels upward, how does the vertical velocity change? Question 9 options: Vertical velocity remains the same. Vertical velocity decreases. Vertical velocity is zero. Vertical velocity increases. Question 10 (10 points) In the simulation above, as the projectile travels downward, how does the vertical velocity change? Question 10 options: Vertical velocity decreases. Vertical velocity is zero. Vertical velocity remains the same. Vertical velocity increases.\

Answer 1

Answer to Q 1:

The path a projectile takes is called Trajectory

Step-by-step explanation:

In terms of projectile motion, trajectory is the curved path that an object follows when it travels in space. It has two components x and y. X component shows the range while y component shows the height of the projectile.

Answer to Question 2

The odd choice out of these options is A person sitting in a chair, not moving

Step-by-step explanation:

For a projectile motion, movement is necessary in a curved path. Since the person sitting in a chair is not moving and he is in rest so he cannot be considered as moving.

Answer to Question 3

The distance will be 490 meters

Step-by-step explanation:

According to second equation of motion

S= vit + ½ gt²

Putting the values

S = 0 + ½ (9.8) (10)

S = 490 meters

Answer to Question 4

The speed will be 65m/s

Step-by-step explanation:

As we know that

Speed = Distance / Time

So putting the values

Speed = 650 / 10

Speed = 65 m/s

Answer to Q 5:

The given statement is true

Step-by-step explanation:

A projectile motion is composed up of two components. X component is responsible for showing the range and Y component is responsible for the height of the projectile.

Answer to Q 6

The given statement is false

Step-by-step explanation:

The shape of projectile graph is a parabola, not an ellipse. The equation of a projectile gives us two values at two different points. Since it is a quadratic equation so that is why this type of motion gives parabola and not an ellipse.

Answer 7:

The false statement is vertical component is always equals to horizontal component.

Step-by-step explanation:

The horizontal component of a projectile is X and it is constant which means no force is acting on it whereas y component has a force of gravity so both of these components can never be the same.

Answer to Q 8:

During the course of trajectory, the horizontal component of the velocity is constant.

Step-by-step explanation:

The horizontal component of trajectory is the X component. This component does not have any force upon it except the force of friction of earth and object. The force of friction is also acting in x axis that is why we can say that during the course of trajectory, the horizontal component of the velocity is constant.

Answer to Q 9

In the simulation above, as the projectile travels upward, its vertical velocity decreases

Step-by-step explanation:

Whenever an object moves against the force of gravity, it’s acceleration and velocity decreases because the gravitational pull tends the object to stay it on earth surface.

Answer to Q 10

In the simulation above, as the projectile travels downward, the vertical velocity increases

Step-by-step explanation:

As the body comes towards the earth the gravitational acceleration increases with the rate of 9.8m/s². This acceleration is taken as positive and when the projectile hits the ground it is in its maximum speed.

Answer 2

1. Parabola

The path taken by a projectil is known as parabola, and it consists of two independent motions:

- along the horizontal direction, it is a uniform motion with constant speed

- along the vertical direction, it is an accelerated motion with constant acceleration, g=9.8 m/s^2 downward

2. A person sitting in a chair, not moving

This is NOT a motion of a projectile. In fact, the person is not moving at all, so this is not a motion.

3. 490 meters

The supplies will move of uniform accelerated motion, with constant acceleration g=9.8 m/s^2, so the distance they cover is given by

`S=(1)/(2)gt^2=(1)/(2)(9.8 m/s^2)(10 s)^2 =490 m`

4. 65 m/s

The horizontal motion of the supplies is a uniform motion, with constant speed equal to the ratio between the horizontal distance covered and the time taken:

`v=(d)/(t)=(650 m)/(10 s)=65 m/s`

5. True

As explaned in exercise 1), a projectile has two independent motions: one along the horizontal direction and one along the vertical direction. Therefore, it also has a horizontal component of the velocity (which is constant) and a vertical component of the velocity (which changes because there is an acceleration acting along this direction)

6. False

As stated in exercise 1) and 2) the trajectory of a projectile is a parabola, not an ellipse.

7. The vertical component always equals the horizontal component

This statement is not true: as we said, the horizontal component of the velocity is constant, while the vertical component constantly changes, so they cannot be always equal (in fact, they will be equal only at some precise instant of the motion)

8. constant

As stated before, there is no force acting along the horizontal direction of the projectile's motion, so the horizontal acceleration is zero, and this means that the horizontal velocity is constant.

9. Vertical velocity decreases.

When the projectile is moving upward, its vertical velocity decreases, because the acceleration (which acts downward) acts in the opposite direction of the velocity. More specifically, the vertical velocity is given by

`v_y(t)=v_(0y)-gt`

where v0y is the initial vertical velocity of the projectile, t is the time and g=9.8 m/s^2.

10. Vertical velocity increases.

When the projectile is moving downward, its vertical velocity increases, because the acceleration (which acts downward) this time is acting in the same direction of the velocity