Answer:
Work is done by the heart on the blood during this time is 0.04 J
Explanation:
Given :
Mass of blood pumped, m = 80 g = 0.08 kg
Initial speed of the blood, u = 0 m/s
Final speed of the blood, v = 1 m/s
Initial kinetic energy of blood is determine by the relation:
Final kinetic energy of blood is determine by the relation:
Applying work-energy theorem,
Work done = Change in kinetic energy
W = E₂ - E₁
Substitute the suitable values in the above equation.
W = 0.04 J
<em>Inertia</em> is the property of all matter by which it tends to remain in constant, uniform motion until it's acted on by an external force.
Answer:
the distance traveled by the car is 42.98 m.
Explanation:
Given;
mass of the car, m = 2500 kg
initial velocity of the car, u = 20 m/s
the braking force applied to the car, f = 5620 N
time of motion of the car, t = 2.5 s
The decelaration of the car is calculated as follows;
-F = ma
a = -F/m
a = -5620 / 2500
a = -2.248 m/s²
The distance traveled by the car is calculated as follows;
s = ut + ¹/₂at²
s = (20 x 2.5) + 0.5(-2.248)(2.5²)
s = 50 - 7.025
s = 42.98 m
Therefore, the distance traveled by the car is 42.98 m.
You know that when the displacement is equal to the amplitude (A), the velocity is zero, which implies that the kinetic energy (KE) is zeero, so the total mechanical energy (ME) is the potential energy (PE).
And you know that the potential energy, PE, is [ 1/2 ] k (x^2)
Then, use x = A, to calculate the PE in the point where ME = PE.
ME = PE = [1/2] k (A)^2.
At half of the amplitude, x = A/2 => PE = [ 1/2] k (A/2)^2
=> PE = [1/4] { [1/2]k(A)^2 } = .[1/4] ME
So, if PE is 1/4 of ME, KE is 3/4 of ME.
And the answer is 3/4
