Answer:
It will be A. So since its 2 times more the kinetic energy. But then you have to square it 2^2 = 4
I think the best way to answer to this kind of question because some of the elements are missing specially the mass of the book is just states the variables and assigned as the mass of an object. So the initial velocity of an object starts at zero and increase rapidly by 9.8 m/s^2 because it is due to gravity
Answer:
50 N
Explanation:
given,
mass of ball = 1 Kg
initial velocity = 3 m/s
final velocity = 2 m/s
time = 0.10 s
impulse = change in momentum
I = m ( v - u)
I = 1( 2 -(-3))
I = 5 kg.m/s
Force is equal to impulse per unit time
average force = 
= 
= 50 N
Average force on the floor will be equal to 50 N
Answer:
a) N = 7.90 10³ N, b) N = -1.04 10⁴ N
Explanation:
a) For this exercise we can use Newton's second law
N -W = m (-a)
The relationship is centripetal, the negative sign of the acceleration is because it points towards the center of the circle
a = v² / r
we substitute
N = mg -m v² /r
N = m (g - v² /r)
let's calculate
v = 8.7 m / s
N = 1240 (9.81 - 8.7²/22)
N = 7.90 10³ N
b) v = 20 m / s
N = 1240 (9.81 - 20²/22)
N = -1.04 10⁴ N
