Answer:
7.328m/s
Explanation:
Given parameters:
height of table = 0.68m
final velocity of the ball = 6m/s
Unknown:
Initial velocity of ball = ?
Solution:
To solve this problem, we are going to employ the appropriate motion equation.
We must understand that this fall occurs in the presence of gravity;
V = U + 2gH
Where;
V is the final velocity
U is the initial velocity
g is the acceleration due to gravity
H is the height of the pool table
Since U is the unknown, let us make it the subject of the expression;
U = V - 2gH
U = 6 - (2 x 9.8 x 0.68) = 7.328m/s(deceleration)
Answer: (d)
Explanation:
Given
Mass of the first ram 
The velocity of this ram is 
Mass of the second ram 
The velocity of this ram 
They combined after the collision
Conserving the momentum
![\Rightarrow m_1v_1+m_2v_2=(m_1+m_2)v\\\Rightarrow 49\times (-7)+52\times (9)=(52+49)v\\\Rightarrow v=\dfrac{125}{101}\ m/s \quad[\text{east}]](https://tex.z-dn.net/?f=%5CRightarrow%20m_1v_1%2Bm_2v_2%3D%28m_1%2Bm_2%29v%5C%5C%5CRightarrow%2049%5Ctimes%20%28-7%29%2B52%5Ctimes%20%289%29%3D%2852%2B49%29v%5C%5C%5CRightarrow%20v%3D%5Cdfrac%7B125%7D%7B101%7D%5C%20m%2Fs%20%5Cquad%5B%5Ctext%7Beast%7D%5D)
Momentum after the collision will be

Therefore, option (d) is correct
Answer:
7.36 × 10^22 kg
Explanation:
Mass of the man = 90kg
Weight on the moon = 146N
radius of the moon =1.74×10^6
Weight =mg
g= weight/mass
g= 146/90 = 1.62m/s^2
From the law of gravitational force
g = GM/r^2
Where G = 6.67 ×10^-11
M = gr^2/G
M= 1.62 × (1.74×10^6)^2/6.67×10^-11
= 4.904×10^12/6.67×10^-11
=0.735×10^23
M= 7.35×10^22kg. (approximately) with option c