How much force is needed to have a 50 kg object accelerate at a rate of 5 m/s²?

 (13.89 - 5.56) m/s /30 s = 8.33 / 30 = 0.278 m/s^2 

F = MA 
F = 150 kg * 0.278 = 41.65 N  

#2) Newton's Equations of motion 

distance = 0.5 * acceleration * time^2 + original velocity * time 
velocity = acceleration * time + original velocity 

First we need acceleration 

F = MA 
7 N = 0.4 kg*A (NOTE: I converted to consistent units: kg, m, s) 
A = 7/.4 = 17,5 m/s^2 

V = at + Vo 
80 m/s = 17.5 /s^2 * t + 0 (Started at rest) 

80 = 17.5 t 
t = 4.57 s 

#3 

First we need the weight of the book on the floor 

F = MA (A = 9.8 m/s^2 the acceleration of gravity) 
F = 0.4 kg * 9.8 m/s^2 = 3.92 N 

Now we need the Net Force on the book slowing it down (A = - 1.5 m/s^2) 

F = MA 
F = 0.4 kg * 1.5 m/s^2 = 0.6 N 

===> Friction is 0.6 N greater than your push or 5.6 N 

Weird!!! That means friction is greater than the weight of the book 

Mu (coff of friction) = Friction Force/Weight = 5.6 / 3.92 = 1,43 ( Nonsense answer) 

#4 We can do as a ratio 

70/400 = 1500/x 
70 x = 600,000 
x = 8,571 N

The charge of an ion with 55 protons and 52 electrons is +3. the reason is because protons are positive, and there are three more than the amount of negative electrons.

Shania is trying to determine the oldest geologic unit on this map and the reason to why is she unable to do so is that  the units are all the same age.. when there is the same age, there will be no oldest geologic unit and that i cannot be credible.