<h2>
Answer:</h2>
(a) 10N
<h2>
Explanation:</h2>
The sketch of the two cases has been attached to this response.
<em>Case 1: The box is pushed by a horizontal force F making it to move with constant velocity.</em>
In this case, a frictional force 
is opposing the movement of the box. As shown in the diagram, it can be deduced from Newton's law of motion that;
∑F = ma -------------------(i)
Where;
∑F = effective force acting on the object (box)
m = mass of the object
a = acceleration of the object
∑F = F -
m = 50kg
a = 0 [At constant velocity, acceleration is zero]
<em>Substitute these values into equation (i) as follows;</em>
F - = m x a
F - = 50 x 0
F - = 0
F = -------------------(ii)
<em>Case 2: The box is pushed by a horizontal force 1.5F making it to move with a constant velocity of 0.1m/s²</em>
In this case, the same frictional force is opposing the movement of the box.
∑F = 1.5F -
m = 50kg
a = 0.1m/s²
<em>Substitute these values into equation (i) as follows;</em>
1.5F - = m x a
1.5F - = 50 x 0.1
1.5F - = 5 ---------------------(iii)
<em>Substitute </em><em> = F from equation (ii) into equation (iii) as follows;</em>
1.5F - F = 5
0.5F = 5
F = 5 / 0.5
F = 10N
Therefore, the value of F is 10N
<em />
im a bit confused on what the question is:(
if its just asking for the total number of km traveled it would be 21 km
A billiard ball collides with a stationary identical billiard ball to make it move. If the collision is perfectly elastic, the first ball comes to rest after collision.
<h3>Why does the first ball comes to rest after collision ?</h3>
Let m be the mass of the two identical balls.
u1 = velocity before the collision of ball 1
u2 = 0 = velocity of second ball that is at rest
v1 and v2 are the velocities of the balls after the collision.
From the conservation of momentum,
∴ mu1 + mu2 = mv1 + mv2
∴ mu1 = mv1 + mv2
∴ u1 = v1 + v2
In an elastic collision, the kinetic energy of the system before and after collision remains same.
∴ 
∴ 
∴ 
₁
₂ = 0
- It is impossible for the mass to be zero.
- Because the second ball moves, velocity v2 cannot be zero.
- As a result, the velocity of the first ball, v1, is zero, indicating that it comes to rest after collision.
<h3>What is collision ?</h3>
An elastic collision is a collision between two bodies in which the total kinetic energy of the two bodies remains constant. There is no net transfer of kinetic energy into other forms such as heat, noise, or potential energy in an ideal, fully elastic collision.
Can learn more about elastic collision from brainly.com/question/12644900
#SPJ4
<span>The density of fissionable uranium is not high enough. Basically more neutrons are absorbed than are produced so any chain reaction dies. hope this helps</span>
Answer:
a) Vi = 137.2 m/s
b) h = 960.4 m
Explanation:
a)
In order to find the initial speed we will use first equation of motion:
Vf = Vi + gt
where,
Vf = Final velocity = 0 m/s (since ball stops at highest point)
Vi = Initial Velocity = ?
g = - 9.8 m/s² (negative sign for upward moyion)
t = time interval = 14 s
Therefore,
0 m/s = Vi + (-9.8 m/s²)(14 s)
<u>Vi = 137.2 m/s</u>
<u></u>
b)
Now, we use second equation of motion to find height (h):
h = Vi t + (1/2)gt²
h = (137.2 m/s)(14 s) + (1/2)(-9.8 m/s²)(14 s)²
h = 1920.8 m - 960.4 m
<u>h = 960.4 m</u>
