Op here is another problem exactly like that. Just plug in your variables instead. And remember, time is never negative.
Answer:
2.85 s .
Explanation:
y(t) = y(0) + v₀t + 1/2 gt²
y(t) is vertical displacement , y(0) is initial position , v₀ is initial velocity and t is time required to make vertical displacement and g is acceleration due to gravity.
Here y(0) is zero , v₀ = 14 m/s , g = 9.8 m s⁻² , y(t ) = 0 , as the pumpkin after time t comes back to its initial position, that is ground .
We shall take v₀ as negative as it is in upward direction and g as positive as it acts in downward direction
Put the values in the equation above,
0 = 0 - 14t + 1/2 x 9.8 t²
14 t = 1/2 x 9.8 t²
t = 28 / 9.8
t = 2.85 s .
The correct answer is: +5
Explanation:
An object is placed at 0; it means:
Initial position of the object = 0.
Now it moves to 3 units to right, so keeping the standard cartesian coordinate system in mind (in right right x-axis is positive and left x-axis is right), the new position of the object will be +3.
Object now moves 4 units to the left, it means +3 - 4 = -1; object is at the position -1.
Object then moves 6 units to the right, therefore,
Final position of the object = -1 + 6 = +5.
Displacement = Final position - Initial position
Displacement = +5 - 0 = +5
The efficiency of the machine is defined as
Here
Work out is the work output and Work in is the work input
To find the Work in we have then
Replacing with our values
The work done by the applied force is
W = Fd
Here,
F = Force
d = Distnace
Rearranging to find F,
F = 129.77N
Therefore the force exerted on the machine after rounding off to two significant figures is 130N
