Rock 3, because it has the most mass while still moving at the same speed, it is kinetic because there is movement and energy being used
Answer:
0.426 volts
Explanation:
It is given that,
The radius of a circular loop, r = 11.2 cm = 0.112 m
An elastic conducting material is stretched into a circular loop.
It is placed with its plane perpendicular to a uniform 0.880 T magnetic field.
The radius of the loop starts to shrink at an instantaneous rate of 68.8 cm/s, dr/dt = 0.688 m/s
We need to find the emf induced in the loop at that instant.
So, the magnitude of induced emf is 0.426 volts.
Work = force x distance
200 Newtons x 20 meters
= 4,000 Joules
<h2>
Speed of motorboat is 36 km/hr and speed of current is 4 km/hr.</h2>
Explanation:
Let speed of motor boat be m and speed of current be c.
A motorboat traveling with a current can go 160 km in 4 hours.
Distance = 160 km
Time = 4 hours
Speed = m + c
We have
Distance = Speed x Time
160 = (m+c) x 4
m + c = 40 --------------------- eqn 1
Against the current it takes 5 hours to go the same distance.
Distance = 160 km
Time = 5 hours
Speed = m - c
We have
Distance = Speed x Time
160 = (m-c) x 5
m - c = 32 --------------------- eqn 2
eqn 1 + eqn 2
2m = 40 + 32
m = 36 km/hr
Substituting in eqn 1
36 + c = 40
c = 4 km/hr
Speed of motorboat is 36 km/hr and speed of current is 4 km/hr.
