Answer:
A. 20 N
Explanation:
Weight of the book = mass × acceleration due to gravity
= 2 × 10
= 20 N
Fine, lets do a retry of this.
Δd = -0.9m
v₁ = 0
v₂ = ?
a = -9.8 m/s²
Δt = ?
We can use the following kinematic equation and solve for Δt.
Δd = v₁Δt + 0.5(a)(Δt)²
Δd = 0.5(a)(Δt)²
2Δd = a(Δt)²
√2Δd/a = Δt
√2(-0.9m)/(-9.8 m/s²) = Δt
0.<u>4</u>28571428574048 = Δt
Therefore, it takes 0.4 seconds for the glass to hit the ground, or 0.43s as you said (even though I don't believe it follows significant digit rules)
Answer:
a lens that causes parallel light rays to separate from each other
Answer:
Explanation:
Given
mass m collides elastically with floor and jump to its original height I .e.velocity of rebound is same as the initial velocity
Impulse imparted by steel ball to the ground is given by the change in momentum of steel ball

and impulse is product of average force and time
so we need time to calculate the average force. So, option e is correct