A 500 g ball swings in a vertical circle at the end of a 1.4-m-long string. when the ball is at the bottom of the circle, the tension in the string is 18 n.
Answer:
27 Joules.
Explanation:
use the formula for kinetic energy:
KE = 1/2mv^2
Answer:
Potential at B would be 100V
Explanation:
The electric potential is defined as the work done to bring a unit positive charge from infinity to some point in the field.
We always determine the potential with respect to some reference point. Let the potential at A be zero. If the potential at B is V, then work done to bring charge q from A to B = qV
which is the electric potential energy.
If instead we use some charge Q, the electric potential <em>energy</em> will be QV, but the electric potential will always be V.
Answer:
The answer is explained below.
Explanation:
All the point on the disk has same angular acceleration. Here, the point P is at the midway between the center and the rim of the disk and the point Q is at rim of the disk.
So, the distance of the point Q from the axis is twicee the distance of the point P from the axis.
<em>Rp - R</em>
<em>Rq - 2R</em>
The linear acceleration is
α2 - Rα
So, the linear acceleration of Q is twice as great as the linear acceleration of P.
The speed of the particle when it is in the circular motion depends on the radius of the particle.
In this case, the speed of point Q is twice the speed of point P.
Answer:
-35 m/s
Explanation:
Momentum is conserved.
Momentum before firing = momentum after firing
m₁u₁ + m₂u₂ = m₁v₁ + m₂v₂
Before the bullet is fired, the bullet and rifle have no velocity, so u₁ and u₂ are 0.
0 = m₁v₁ + m₂v₂
Given m₁ = 0.7 kg, v₁ = 350 m/s, and m₂ = 7 kg:
0 = (0.7 kg) (350 m/s) + (7 kg) v
v = -35 m/s
The rifle recoils at 35 m/s in the opposite direction.
