If you pull horizontally on a desk with a force of 150 N and the desk doesn't move, the friction force must be 150 N. Now if you
1 answer:
Answer:
The friction force is 250 N
Explanation:
The desk is moving at constant velocity. This means that its acceleration is zero: a = 0. Newton's second law states that the resultant of the forces acting on the desk is equal to the product between mass (m) and acceleration (a):
In this case, we know that the acceleration is zero: a = 0, so also the resultant of the forces must be zero:
(1)
We are only interested in the forces acting along the horizontal direction, since it is the direction of motion. There are two forces acting in this direction:
- the pull, forward, F = 250 N
- the friction force, backward,
Given (1), we have
So the force of friction must be equal to the pull:
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Answer:
22.26 years
, 15.585 light years , 11.13 light years
Explanation:
a)
=
= 22.26 years
b)
0.7*c*22.26 years
=15.585 light years
c)
0.7*c*15.9
=11.13 light years
Answer:
The range of the bullet is 0.435 kilometers.
Explanation:
According to the problem, maximum height is equal to the range of the bullet. That is:
Where:
- Range of the bullet, measured in meters.
- Maximum height of the bullet, measured in meters.
By the Principle of Energy Conservation, gravitational potential energy reaches its maximum at the expense of the initial kinetic energy. That is to say:
Where:
- Kinetic energy at point 1, measured in joules.
- Gravitational potential energy at point 2, measured in joules, and:
Where:
- Mass of the bullet, measured in kilograms.
- Gravitational constant, measured in meters per square second.
The maximum height is now cleared:
If ,
and
, the maximum height is now computed:
Lastly, the range of the bullet is 0.435 kilometers.