Answer: 1.77 s
Explanation: In order to solve this problem we have to use the kinematic equation for the position, so we have:
xf= xo+vo*t+(g*t^2)/2 we can consider the origin on the top so the xo=0 and xf=29 m; then
(g*t^2)/2+vo*t-xf=0 vo is the initail velocity, vo=7.65 m/s
then by solving the quadratric equation in t
t=1.77 s
Explanation:
by finding the distance between two successful crest
Answer:
1. the electric potential energy of the electron when it is at the midpoint is - 2.9 x 
J
2. the electric potential energy of the electron when it is 10.0 cm from the 3.00 nC charge is - 5.04 x J
Explanation:
given information:
= 3 nC = 3 x 
C
= 2 nC = 2 x C
r = 50 cm = 0.5 m
the electric potential energy of the electron when it is at the midpoint
potential energy of the charge, F
F = k 
where
k = constant (8.99 x 
)
electron charge, 
= - 1.6 x 
C
since it is measured at the midpoint,
r = 
= 0.25 m
thus,
F = 
= k
+ k
= 
(
)
= (8.99 x 
)( - 1.6 x )(3 x +2 x )/0.25
= - 2.9 x J
the electric potential energy of the electron when it is 10.0 cm from the 3.00 nC charge
= 10 cm = 0.1 m
= 0.5 - 0.1 = 0.4 m
F = k + k
= 
(
+
)
= (8.99 x )( - 1.6 x )(3 x /0.1+2 x /0.4)
= - 5.04 x J
Answer:
Given:
Bone density = 2.0 kg/m³
Volume of bone (V) = 0.00027 m³
To Find:
Mass of an adult femur bone (m).
Explanation:
To solve this problem we will apply the principles of energy conservation. On the one hand we have that the work done by the non-conservative force is equivalent to -30J while the work done by the conservative force is 50J.
This leads to the direct conclusion that the resulting energy is 20J.
The conservative force is linked to the movement caused by the sum of the two energies, therefore there is an increase in kinetic energy. The decrease in the mechanical energy of the system is directly due to the loss given by the non-conservative force, therefore there is a decrease in mechanical energy.
Therefore the correct answer is A. Kintetic energy increases and mechanical energy decreases.
