Answer:
78.4 m
Explanation:
Using newton's equation of motion,
S = ut + 1/2gt²......................... Equation 1
Where S = Height, t = time, u = initial velocity, g = acceleration due to gravity.
Note: Taking upward to be negative, and down ward positive
Given: u = 49 m/s, t = 2.0 s, g = -9.8 m/s²
Substitute into equation 1
S = 49(2) - 1/2(9.8)(2)²
S = 98 - 19.6
S = 78.4 m
Hence the height of the ball two seconds later = 78.4 m
Answer:
1.6 ft/min
Explanation:
Since trough is 10 ft long and water is filled at the rate of 12ft3/min. We can calculate the rate of water filled with respect to area:
= 12 / 10 = 1.2ft2/min
As the water level rises, so does the water surface, or the bottom side of the isosceles triangles. In fact we can calculate the bottom side when the trough is half foot deep:
= 3 / 2 = 1.5 ft
The rate of change in water level would be the same as calculating the height of the isosceles triangles knowing its base
= 1.2 * 2 / 1.5 = 1.6 ft/min
Answer:
Woke done, W = 4156.92 Joules
Explanation:
The work done by the force can be calculated as :
is the angle between force and the displacement
It is assumed to find the work done for the given parameters i.e.
Force, F = 30 N
Distance travelled, s = 160 m
Angle between force and displacement, 
Work done is given by :
W = 4156.92 Joules
So, the work done by the object is 4156.92 Joules. Hence, this is the required solution.
Solution :
Given weight of Kathy = 82 kg
Her speed before striking the water, 
= 5.50 m/s
Her speed after entering the water, 
= 1.1 m/s
Time = 1.65 s
Using equation of impulse,
Here, F = the force ,
dT = time interval over which the force is applied for
= 1.65 s
dP = change in momentum
dP = m x dV
![$= m \times [V_f - V_o] $](https://tex.z-dn.net/?f=%24%3D%20m%20%5Ctimes%20%5BV_f%20-%20V_o%5D%20%24)
= 82 x (1.1 - 5.5)
= -360 kg
∴ the net force acting will be
= 218 N
Your answer is C) <span> the potential energy of an object is always greater than its kinetic energy </span>
