Explanation:
work input is the work done by the machine in lifting the drum = Force × distance
100N × 10m
= 1000 J
Answer:
Explanation:
Force F = 20 t² N so force is variable.
friction on the crate = mgμ , μ is coefficient of kinetic friction , m is mass
Net force
= F - mgμ
= 20 t² - mgμ = m dv / dt ( Newton's 2 nd law )
m dv = (20 t² - mgμ ) dt
Integrating on both sides,
m v = 20 (t³ / 3) - mgμ t
Putting the values ,
25 x v = 20 x 4³/3 - 25 x 9.8 x .25 x 4
25 v = 426.67 - 245
25 v = 181.67
v = 7.27
v = 7.27 m /s
Answer:
to the left.
Explanation:
We can use the equation where v is the velocity at time t and the velocity at . Since we want the acceleration we write this equation as:
Considering the <em>direction to the right as the positive one</em>, we have at , and at , so we substitute:
Where the minus sign indicates it is directed to the left.
Answer:
88.2J
Explanation:
Given parameters:
Mass of book = 3kg
Height of shelf = 3m
Unknown:
Potential energy = ?
Solution:
The potential energy of a body is the energy due to the position of that body.
It can be mathematically calculated as;
P.E = mgh
m is the mass of the body
g is the acceleration due to gravity = 9.8m/s²
h is the height
Now insert the parameters and solve;
P.E = 3 x 9.8 x 3 = 88.2J
Sensible heat involves a change in temperature.