Answer with explanation:
We are given that
Mass of ball,
75 g=
1 kg=1000 g
Height,

Horizontal velocity,
Mass of plate
a.Initial velocity of plate,
Velocity before impact=
Where 
Velocity after impact,
According to law of conservation of momentum

Substitute the values



Velocity of plate=1.69 m/s
b.Initial energy=
Final energy=
Final energy=
Energy lost due to compact=Initial energy-final energy=1.326-1.162=0.164 J
Answer:
2 /s north
Explanation:
Given that,
Velocity due North is 8 m/s and due south is 6 m/s
We need to find the magnitude and the direction of the resulting velocity.
Let North is positive and South is negative. When two velocities are in opposite direction, they adds up. So,

It is positive. So, it is in North direction.
<h3>Answer</h3>
6.6 N pointing to the right
<h3>Explanation</h3>
Given that,
two forces acting of magnitude 3.6N
angle between them = 48°
To find,
the third force that will cause the object to be in equilibrium
<h3>1)</h3>
Find the vertical and horizontal components of the two forces
vertical force1 = sin(24)(3.6)
vertical force2= -sin(24)(3.6)
<em>(negative sign since it is acting on opposite direction)</em>
vertical force3 = sin(24)(3.6) - sin(24)(3.6)
= 0
<h3>2)</h3>
horizontal force1 = cos(24)(3.6)
horizontal force2= cos(24)(3.6)
horizontal force3 = cos(24)(3.6) + cos(24)(3.6)
= 2(cos(24)(3.6))
= 6.5775 N
≈ 6.6 N
<em />
<em />
The correct answer is
<span>c. one person exerts more force than the other so that the forces are unbalanced.
In fact, the door is initially at rest. In order to move the door, a net force different from zero should be applied, according to Newton's second law:
</span>

<span>where the term on the left is the resultant of the forces acting on the door, m is the door mass and a its acceleration.
In order to move the door, the acceleration must be different from zero. But this means that the resultant of the forces acting on it must be different from zero: this is possible only if the forces applied by the two persons are unbalanced, i.e. one person exerts more force than the other.</span>