Answer:
-2.5m/s²
Explanation:
The acceleration of a body is giving by the rate of change of the body's velocity. It is given by
a = Δv / t ----------------(i)
Where;
a = acceleration (measured in m/s²)
Δv = change in velocity = final velocity - initial velocity (measure in m/s)
t = time taken for the change (measured in seconds(s))
From the question;
i. initial velocity = 5m/s
final velocity = 0 [since the body (ball) comes to rest]
Δv = 0 - 5 = -5m/s
ii. time taken = t = 2s
<em>Substitute these values into equation (i) as follows;</em>
a = (-5m/s) / (2s)
a = -2.5m/s²
Therefore, the acceleration of the ball is -2.5m/s²
NB: The negative sign shows that the ball was actually decelerating.
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
Answer:
284.4233 N/m
Explanation:
k = Spring constant
x = Compression of spring = 14.5 cm
U = Potential energy = 2.99 J
The potential energy of a spring is given by

Rearranging to get the value of k

The spring constant is 284.4233 N/m
Answer:
0.98kW
Explanation:
The conservation of energy is given by the following equation,


Where
Mass flow
Specific Enthalpy (IN)
Specific Enthalpy (OUT)
Gravity
Heigth state (In, OUT)
Velocity (In, Out)
Our values are given by,




For this problem we know that as pressure, temperature as velocity remains constant, then


Then we have that our equation now is,


