All Questions
26
questions
0
votes
5
answers
123
views
Vertical motion under gravity
If we project an object vertically under gravity it travels vertically upwards until vertical velocity zero, why is that? Why does the velocity become zero?
- 21
-2
votes
2
answers
154
views
Why does the size of the ball change?
I am reading Head First Physics.
On page 372 it states that the size of the ball changes. I have checked my previous notes, but I cannot understand why?
Here is a picture of the page:
- 117
0
votes
7
answers
387
views
Vertical motion of an object
We define acceleration as $-9.8\frac{m}{s^2}$ for an object that is thrown upwards due to gravity. My question is when the object reaches maximum height at the point where it is about to turn around ...
- 23
1
vote
1
answer
463
views
How to determine where an object will land on a variable elevation surface?
I'm making a game and I need to figure out the exact point on a hilly surface where the car will land after the jump.
Here is an image:
So since this is a game, it's very easy for me to figure out ...
- 13
1
vote
1
answer
47
views
Calculating a free fall vector so its equals to its inverse vector while accounting for gravity
I'm a game developer, and I've been struggling with a kinematics problem in the development process of my current project.
I have some stationary objects that are suddenly affected by gravity after a ...
- 13
-1
votes
2
answers
384
views
Will a bullet fired from a gun perpendicular to the surface of Earth return? [duplicate]
How will a bullet having very high velocity and having little mass behave when fired from the Earth perpendicular to the surface? It will be a great help if somwone explained it? Will it come back? ...
0
votes
7
answers
38k
views
Why will a dropped object land at the same time as a sideways thrown one? [duplicate]
My textbook says that a ball dropped vertically and a ball thrown sideways will not only both land simultaneously but their height will be corresponding for the entire fall, as shown in a diagram ...
- 2,356
0
votes
3
answers
1k
views
Does a ball, when thrown into the air, ever experience an instant of rest? [duplicate]
Say I walk outside and throw a ball into the air. Obviously it will decelerate as it travels upward due to Earth's gravity, and accelerate as it travels downward for the same reason. But is the ball ...
- 163
0
votes
3
answers
20k
views
Kinematics of bouncing ball
If we model the motion of a bouncing ball on a velocity time graph, neglecting air resistance, we get a line with gradient -9.8 as the ball falls , and then a steep positive gradient line when the ...
- 11
1
vote
1
answer
566
views
Simple explanation of why object falls in same time it takes to go up?
I was following through The Secret Life Of Equations by Rich Cochrane, and in the chapter on Newton's Second Law, there is a example: given an object of mass $1\, kg$, thrown up at $20\, m/s$ by ...
user146934
0
votes
1
answer
130
views
Direction of $g$ acceleration ball projection
Why is the answer A? Because I thought it's C, because g acts downward and since the ball is moving downwards towards N, acceleration should be "g" and not "-g" as it was when it was being thrown up ...
0
votes
1
answer
10k
views
Projectile on an inclined plane [closed]
Say you have the classic problem of a projectile going at 10m/s at 15 degrees off a plane already inclined at 30 degrees (so the projectile's angle with respect to the earth is 45 degrees), and you ...
- 307
0
votes
1
answer
314
views
Motion of an object in a varying gravitational field
Let $E(x,y,z)$ denote the gravitational field,
then in an uniform gravitational field( $E(x,y,z) = k$), the equation
$\mathbf{s(t)} = \mathbf{u}t + \frac{1}{2}kt^2 $ holds (where $\mathbf{s}$ is ...
- 155
-3
votes
2
answers
150
views
Use equations to create a realistic problem [closed]
Given the following equations:
$100$ m = $0$ m + ($50 \cos\theta$ m/s)$t_1$
$0$ m = $0$ m + ($50 \sin\theta$ m/s)$t_1$ - $\frac{1}{2}(9.80$ m/s2$) t_1^2$
I am supposed to make up/create a real-life ...
4
votes
4
answers
2k
views
Calculating how fast a mass needs to travel in order to launch itself from a hill
Today I was driving on a hill side and on the opposite lane this very careless gentleman was traveling at a very high speed on a large truck that I surely thought his truck would of lifted off the ...
- 757