Answer: Speed = 4m/s
Strength = 7.1T
Explanation: P= 4.0w
N = 1.0
V= ?
Power = force x velocity
Velocity = power/ force
V= 4.0w/1.0N
V = 4m/s
Strength of the magnetic field
B = √PR / lv
Where; l = length 10cm
R= 2.0
P= 4.0w
V= 4m/s
B = √ (4.0w) × (2.0) / (10cm) × (4m/s)
B = 7.1T
The mechanical energy at top =Mechanical energy at bottom
- Mass=m=54kg
- Height=h=51m
- Acceleration due to gravity=g=10m/s^2
- Velocity=v=2.6m/s

- Final energy at bottom=The kinetic energy










Answer:
Because it is said that the earth rotates and revolves around the sun and moon so it is impossible for the earth not to be spinning.
Explanation:
Answer:
C)It would require more energy to change solid water into liquid water because there are more molecules in this larger piece of ice.
Answer:
a)11.25 J
b)Number of revolution = 1
Explanation:
Given that
Radius ,r= 0.8 m
m= 0.3 kg
Initial speed ,u= 10 m/s
final speed ,v= 5 m/s
a)
Initial energy


KEi= 15 J
Final kinetic energy


KEf=3.75 J
The energy transformed from mechanical to internal = 15 - 3.75 J = 11.25 J
b)
The minimum value to complete the circular arc

Now by putting the values

V= 2.82 m/s
So kinetic energy KE


KE=1.19 J
ΔKE= KEi - KE
ΔKE= 15- 1.19 J
ΔKE=13.80 J
The minimum energy required to complete 2 revolutions = 2 x 11.25 J
= 22.5 J
Here 22.5 J is greater than 13.8 J.So the particle will complete only one revolution.
Number of revolution = 1