Answer:
20.42 N/m
Explanation:
From hook's law,
F = ke ......................... Equation 1
Where F = Force applied to the spring., k = spring constant, e = extension.
Make k the subject of the equation,
k = F/e ................. Equation 2
Note: The force on the spring is equal to the weight of the mass hung on it.
F = W = mg.
k = mg/e................ Equation 3
Given: m = 250 g = 0.25 kg, e = 37-25 = 12 cm = 0.12 m.
Constant: g = 9.8 m/s²
Substitute into equation 3
k = (0.25×9.8)/0.12
k = 20.42 N/m.
Hence the spring constant = 20.42 N/m
The correct answer is
<span>B. if Earth rotated on an axis that was not tilted with respect to Earth's orbit
In fact, the fact that Earth's axis is tilted is the reason why the durations of day and night are different in every part of the Earth. If the axis was not tilted, we would have exactly 12 hours of day and night in every point of the Earth, for the whole year.</span>
Answer:
No
Explanation:
The force of tension exerted by the string on the rock acts as centripetal force, so its direction is always towards the centre of the circle.
However, the direction of motion of the rock is always tangential to the circle: this means that the force is always perpendicular to the direction of motion of the rock.
As we know, the work done by a force on an object is
where
F is the magnitude of the force
d is the displacement of the object
is the angle between the force and the displacement
In this situation, F and d are perpendicular, so 
, therefore 
and the work done is zero:
Answer:
it's possible to calculate an object's velocity at any moment along its path. This is called instantaneous velocity and it is defined by the equation v = (ds)/(dt),in other words, the derivative of the object's average velocity equation.
Answer:
1.97 * 10^8 m/s
Explanation:
Given that:
n = 1.52
Recall : speed of light (c) = 3 * 10^8 m/s
Speed (v) of light in glass:
v = speed of light / n
v = (3 * 10^8) / 1.52
v = 1.9736 * 10^8
Hence, speed of light in glass :
v = 1.97 * 10^8 m/s
