Answer:
+5.4×10⁻⁷ C
Explanation:
Electric potential: This can be defined as the work done in bringing a unit charge from infinity to that point against the action of the field. The S.I unit of potential is volt (V)
The formula for potential is
V = kq/r............................ Equation 1
Where V = electric potential, k = proportionality constant, q = charge, r = distance.
making q the subject of the equation,
q = Vr/k............................ Equation 2
Given: V = 490 V, r = 10 m,
Constant: k = 9×10⁹ Nm²/C²
Substitute into equation 2
q = 490(10)/(9×10⁹)
q = 5.4×10⁻⁷ C
q = +5.4×10⁻⁷ C
Hence the charge is +5.4×10⁻⁷ C
In the first case, the force acting on the spring is the weight of the mass:
This force causes a stretching of
on the spring, so we can use these data to find the spring constant:
In the second case, the first mass is replaced with a second mass, whose weight is
And since we know the spring constant, we can calculate the new elongation of the spring:
Answer:
Explanation:
As per mechanical energy conservation we can say that here since friction is present in the barrel so we will have
Work done by friction force = Loss in mechanical energy
so we will have
here we know that
Initial compression in the spring is given as
now from above equation
I like to just keep writing them over and over on a page also if you remember them just before the exam than as soon as you start write them on the front of your test so you don’t forget them.
Hope this helps.
Answer:
The target was higher than the cannon
Explanation:
Given that a cannon ball is launched with initial speed 56 m/s, and hits a target at speed 35 m/s.
The initial velocity must be 56 m/s, while the final velocity will be 35 m/s.
When an object is thrown upward with an initial velocity, the object continues to move upwards with decreasing in magnitude of velocity till it reaches the maximum height where the final velocity will be equal to zero.
In this question, since the final velocity is less than the initial velocity, we can conclude that the target is higher.
Therefore, the target was higher than the cannon.
