Answer:
= 54,000 Joules or 54 kJ
Explanation:
Electrical energy is given by the formula;
E = VIt; where V is the potential difference in volts, I is the current and t is the time in seconds.
Therefore;
Electrical energy = 120 V × 0.50 A × 15 ×60 seconds
= 54,000 Joules
Thus; the electrical energy is 54,000 joules or 54 kJ
Answer:
B.
It will be greater than 10 J.
Explanation:
The total mechanical energy of an object is the sum of its potential energy (PE) and its kinetic energy (KE):
E = PE + KE
According to the law of conservation of energy, when there are no frictional forces on an object, its mechanical energy is conserved.
The potential energy PE is the energy due to the position of the object: the highest the object above the ground, the highest its PE.
The kinetic energy KE is the energy due to the motion of the object: the highest its speed, the largest its KE.
Here at the beginning, when it is at the top of the roof, the baseball has:
PE = 120 J
KE = 10 J
So the total energy is
E = 120 + 10 = 130 J
As the ball falls down, its potential energy decreases, since its height decreases; as a result, since the total energy must remain constant, its kinetic energy increases (as its speed increases).
Therefore, when the ball reaches the ground, its kinetic energy must be greater than 10 J.
Answer: here you go I was looking for this answer everywhere,I have it now so it’s 6.30 x 10^-7 s
Explanation:
I hope this helps☺️
Answer:
Potential energy of spring = 24 Joules.
Explanation:
Given the following data;
Spring constant = 85N/m
Extension, e = 0.75m
Mass = 25kg
To find the potential energy of a spring
Potential energy of a spring is given by the formula;
P.E = ½ke²
Substituting into the equation, we have
P.E = ½*85*0.75²
P.E = 42.5 * 0.5625
P.E = 23.91 ≈ 24 Joules
P.E = 24 Joules
Speed v = initial speed u + acceleration a x time t
v=u+at = 2 + 4*3 = 14 m/s
