All Questions
22
questions
0
votes
2
answers
82
views
Why does a ball bounce back even when it is released and not thrown?
So according to my understanding when we thrown a ball towards ground we apply an additional amount of force which results in an acceleration greater than the one due to earth. When this ball reaches ...
- 45
0
votes
1
answer
222
views
As the speed time graph for a body thrown vertically upwards is not differentiable at the top point so why acc. is taken as 9.8 m/s² at the top point?
In the shown speed - time graph for a body thrown vertically up there is a sharp kink in the graph at the instant for which body is at highest position ie not differentiable so we can't find ...
- 1,357
0
votes
1
answer
281
views
How can a person inside from a veiled and free-falling elevator distinguish whether he is in an inertial or non-inertial frame?
From wikipedia: "A non-inertial reference frame is a frame of reference that undergoes acceleration with respect to an inertial frame", according to that statement, I would say that an ...
- 339
0
votes
1
answer
770
views
Does an object rolling down a slope have more momentum than a object in free fall?
Physics newbie here. I am trying to figure out in which of the following scenarios would the object end up further from the starting point:
Will a car that veers off a road that has a vertical cliff ...
user313522
0
votes
2
answers
100
views
If I throw an object upward will its acceleration change or it will stay constant at $-g$?
I mean if, for example, I throw a rock upward, its acceleration will always be $-g$ or it will be $-g+a$ because I apply a force on the object when I throw it? (without considering friction)
4
votes
4
answers
440
views
Did we just misunderstand gravity?
Einstein told us that a spring balance under free fall shows zero deflection and thus derived that gravity is a curvature in the fabric of spacetime and all those stuffs.
Now let's assume we have a ...
- 8,230
0
votes
2
answers
80
views
Is acceleration in mutual attraction of two particle system is uniform
The gravitational force on a body due to another body is $\frac{Gmm'}{R^2}$ where the mass of the respective bodies are $m$ and $m'$
So the acceleration of one body (say mass $m$) be $\frac{F}{m}$ ...
- 486
0
votes
1
answer
107
views
Why do I feel a force from a non-accelerating punch? [duplicate]
If I'm getting punched by a fist that is moving at a constant velocity (let's say $20 \mathrm{m/s}$), I still feel a force that is being applied to my body. However, according to $F=ma$, in order to ...
0
votes
1
answer
86
views
Whirling a stone parallel to the surface of the earth
Whenever I whirl a stone in a horizontal circle I find that while revolving the string and the stone align in a horizontal plane. But at the same time gravitational force is acting on it which must ...
user238497
2
votes
2
answers
1k
views
Lifting an Object On A Scale
Let's say hypothetically that I'm standing on a scale while holding an object with some mass. If I accelerate the mass upwards (with my hands), will the reading on the scale increase? I've been ...
- 97
0
votes
3
answers
75
views
Is there always acceleration due to gravity?
Say I am standing motionless relative to Earth. My weight is my mass multiplied by my acceleration. My acceleration should be -9.8 m/s/s in this equation, but how am I accelerating without a change ...
- 11
1
vote
2
answers
802
views
Acceleration due to gravity
Does acceleration due to gravity increase when an object at a said radius is doubled? Like for instance, if I said the radius of the earth is $5\, \mathrm{km}$ (not to scale obviously) if I doubled ...
- 13
3
votes
2
answers
285
views
Why is Einstein's "Equivalence principle" that new when Einstein formulates it?
If I understand it correctly (see here for example), the "Equivalence principle" roughly states that "acceleration" has the same effect as "gravity".
But don't we know, since Newton, they are indeed ...
- 153
0
votes
3
answers
28k
views
Acceleration of a ball thrown into the air [duplicate]
A ball sitting in a person's hand is at rest. The ball is thrown into the air. There must be some upward acceleration which is greater than the acceleration due to gravity, since in order for the ball ...
- 103
6
votes
2
answers
1k
views
Does the velocity you travel affect your weight in an elevator?
I know that if you are accelerating upward in an elevator, you will have more weight (if you are on a scale) due to normal force of the elevator pressing up into you? Would that happen if you are ...
- 195