Answer:
a. P.E = 3430Joules.
b. Workdone = 3430Nm
Explanation:
<u>Given the following data;</u>
Mass = 70kg
Distance = 5m
We know that acceleration due to gravity is equal to 9.8m/s²
To find the potential energy;
Potential energy = mgh
P.E = 70*9.8*5
<em>P.E = 3430J</em>
b. To find the workdone;
Workdone = force * distance
But force = mass * acceleration
Force = 70*9.8
Force = 686 Newton.
Workdone = 686 * 5
<em>Workdone = 3430Nm</em>
Answer
B. F=ma
Explanation
The Newton's laws of motion tries to explain the how bodies behave and the energy changes when theys are in motion. For the 3 of them to hold, the bodies must be moving in a straight line and with constant velocity.
The second one states that, "the change of momentum of a moving body is directly proportional to the force producing it and it takes place to the direction of force."
From the choices given, the appropriate answer is B. F=ma
Answer:
354200J
Explanation:
Given parameters:
Mass of copper bushing = 8kg
Initial temperature = 25°C
Final temperature = 140°C
Unknown:
Quantity of heat required to heat this mass = ?
Solution:
The amount of heat required to heat mass from one temperature to another is given by;
H = m c Δt
where m is the mass
c is the specific heat
Δt is the change in temperature
C is a constant and for copper, its value is 385J/kg°C
Input the parameters;
H = 8 x 385 x (140 - 25) = 354200J
D.
This is an accordance with Newton's First Law of Motion, stating that objects in motion remain in motion and objects at rest remain at rest unless acted upon by an external force.
The forces of gravity between two objects depend on the masses
of both objects. So if one mass increases, then the objects will be
drawn together by stronger gravitational force.
Example:
When a person eats a lot of steak and fat and carbohydrates, his
mass increases, and the bathroom scale shows that the gravitational
forces drawing him and the Earth together have increased. We say
that he has "gained weight".
