Answer:
Explanation:
Initial kinetic energy of M = 1/2 M vi²
let final velocity be vf
v² = u² + 2a s
vf² = vi² + 2 (F / M) x D
Kinetic energy
= 1/2 Mvf²
= 1/2 M ( vi² + 2 (F / M) x D
1/2 M vi² + FD
Ratio with initial value
1/2 M vi² + FD) / 1/2 M vi²
RK = 1 + FD / 2 M vi²
<h3>Question 1</h3>
Answer
option C) velocity
Explanation
acceleration = Δv ÷ Δt
<h3>Question 2</h3>
Answer
option C) m/s²
Explanation
Δv ÷ Δt
= m/s ÷ s
= m/s x 1/s
= m/s²
<h3>Question 3</h3>
Answer
option B) velocity has both direction and speed.
That is why velocity can be negative but speed can not and velocity is rate of change of displacement where as speed is rate of change of distance.
Answer:
a)
& 
b) 
c) 
Explanation:
Given:
mass of the book, 
combined mass of the student and the skateboard, 
initial velocity of the book, 
angle of projection of the book from the horizontal, 
a)
velocity of the student before throwing the book:
Since the student is initially at rest and no net force acts on the student so it remains in rest according to the Newton's first law of motion.

where:
initial velocity of the student
velocity of the student after throwing the book:
Since the student applies a force on the book while throwing it and the student standing on the skate will an elastic collision like situation on throwing the book.

where:
final velcotiy of the student after throwing the book
b)



c)
Since there is no movement of the student in the vertical direction, so the total momentum transfer to the earth will be equal to the momentum of the book in vertical direction.



Answer:
Helium
Explanation:
Helium is the least reactive element, since it is a noble gas with the smallest amount of valence rings.
Answer a would be correct since velocity is a vector and has a magnitude and a direction. In this case v₁ = - v₂.