V=at and a=F/m
140/.070 = 2000m/s^2
2000*.020 = 40m/s
The ball’s velocity increased by 40m/s.
PE= 3kg x 10N/kg x 10m
= 300J
Answer:
86605.08 N
Explanation:
The equation to calculate the force is:
Force = mass * acceleration
The force and the acceleration does not have the same direction in this case, so we need to decompose the force into its horizontal component, which is the force that will generate the horizontal acceleration:
Force_x = Force * cos(30)
Then, we have that:
Force_x = mass * acceleration
Force * cos(30) = 25000 * 3
Force * 0.866 = 75000
Force = 75000 / 0.866 = 86605.08 N
Answer:
The current is 
The direction is anti-clockwise
Explanation:
The diagram for this question is shown on the first uploaded image
From the question we are told that
the length of the conducting rod is 
The resistance is 
The magnetic field is 
The speed of the rod is 
The emf induced is
substituting values we have
From ohm law the induced current would be
substituting values we have
The direction anticlockwise this because according to lenze law the current due to change in magnetic field will act in the opposite direction of the force causing the magnetic field to change
Answer:
Kf= 36 J
W(net) = 32 J
Explanation:
Given that
m = 2 kg
F= 4 N
t= 2 s
Initial velocity ,u= 2 m/s
We know that rate of change of linear momentum is called force.
F= dP/dt
F.t = ΔP
ΔP = Pf - Pi
ΔP = m v - m u
v= Final velocity
By putting the values
4 x 2 = 2 ( v - 2)
8 = 2 ( v - 2)
4 = v - 2
v= 6 m/s
The final kinetic energy Kf
Kf= 1/2 m v²
Kf= 0.5 x 2 x 6²
Kf= 36 J
Initial kinetic energy Ki
Ki = 1/2 m u²
Ki= 0.5 x 2 x 2²
Ki = 4 J
We know that net work is equal to the change in kinetic energy
W(net) = Kf - Ki
W(net) = 36 - 4
W(net) = 32 J
