Answer:
5.01×10⁴ J.
Explanation:
Applying,
q = Cm....................... Equation 1
Where q = amount of heat needed to melt the ice, m = mass of the ice, C = specific latent heat of ice.
From the question,
Given: m = 150 g = (150/1000) kg = 0.15 kg, C = 3.34×10⁵ J/kg
Substitute these values into equation 1
q = (0.15×3.34×10⁵)
q = 0.501×10⁵ J
q = 5.01×10⁴ J.
Answer: 17.68 s
Explanation:
This problem is a good example of Vertical motion, where the main equation for this situation is:
(1)
Where:
is the height of the ball when it hits the ground
is the initial height of the ball
is the initial velocity of the ball
is the time when the ball strikes the ground
is the acceleration due to gravity
Having this clear, let's find
from (1):
(2)
Rewritting (2):
(3)
This is a quadratic equation (also called equation of the second degree) of the form
, which can be solved with the following formula:
(4)
Where:



Substituting the known values:
(5)
Solving (5) we find the positive result is:

Answer:
You increase the acceleration of the car.
Answer:
310.5 J
Explanation:
The total work done by Martha is equal to the increase in gravitational potential energy of the package, which is equal to

where
(mg) = 45 N is the weight of the package
is the increase in height of the package
The package is carried up 3 flights of stairs, each one with a height of 2.3 m, so the total increase in heigth is

And so, the work done by Martha is
