<h2>
Time taken is 0.632 seconds</h2>
Explanation:
Impulse momentum theorem is change in momentum is impulse.
Change in momentum = Impulse
Final momentum - Initial momentum = Impulse
Mass x Final velocity - Mass x Initial Velocity = Force x Time
Mass x Final velocity - Mass x Initial Velocity =Mass x Acceleration x Time
Final velocity - Initial Velocity = Acceleration x Time
Final velocity = 9.9 m/s
Initial Velocity = 3.7 m/s
Acceleration = 9.81 m/s²
Substituting
9.9 - 3.7 = 9.81 x Time
Time = 0.632 seconds
Time taken is 0.632 seconds
Answer:
F = 156.3 N
Explanation:
Let's start with the top block, apply Newton's second law
F - fr = 0
F = fr
fr = 52.1 N
Now we can work with the bottom block
In this case we have two friction forces, one between the two blocks and the other between the block and the surface. In the exercise, indicate that the two friction coefficients are equal
we apply Newton's second law
Y axis
N - W₁ -W₂ = 0
N = W₁ + W₂
as the two blocks are identical
N = 2W
X axis
F - fr₁ - fr₂ = 0
F = fr₁ + fr₂
indicates that the lower block is moving below block 1, therefore the upper friction force is
fr₁ = 52.1 N
fr₁ = μ N
a
s the normal in the lower block of twice the friction force is
fr₂ = μ 2N
fr₂ = 2 μ N
fr₂ = 2 fr₁
we substitute
F = fr₁ + 2 fr₁
F = 3 fr₁
F = 3 52.1
F = 156.3 N
-- the big flash of light and heat coming out of the head
of a match when it gets hot enough;
-- the explosion of a tiny bit of gunpowder that can send
a bullet many miles;
-- the energy captured from a few drops of burning gasoline
that moves a car;
-- the energy in the carbohydrates you eat that is used
to move you around;
1,000 W = 1 kW
100 W = 0.1 kW
(0.1 kW) x (6 h) = 0.6 kWh <=== energy
(0.6 kWh) x (£0.1359/kWh) = £0.0815 <=== cost of it
