Friction occurs when the surfaces and heat of two surfaces grind against each other.
I think these are the answers
Answer:
B'=1.935 T
Explanation:
Given that
magnetic field ,B= 0.645 T
We know that magnetic filed in the solenoid is given as

I=Current
n=Number of turn per unit length
μ0 =magnetic permeability
Now when the current increased by 3 factors
I'=3 I
Then the magnetic filed


B'=3 B
That is why
B' = 3 x 0.645 T
B'=1.935 T
Therefore the new magnetic filed will be 1.935 T.
8.16m is the required height, a 5kg stone need to be raised.
One sort of potential energy is gravitational potential energy, which is equal to the product of the object's mass (m), the gravitational acceleration (g), and the object's height (h) as measured in relation to the ground's surface (the body).
We obtain the formula by considering the work done in raising a mass m through a height h.
Work in elevating mass m through height h is equal to force times distance.
The force must be greater than the mass m's weight, hence F = mg.
Work done = mgh = gravitational potential energy
Energy = Mass of the object × gravitational acceleration × height.
Mass of the stone = 5kg
Equating ;
∴ 400 J = 5 kg × 9.8 m/s² × height
Height = 8.16 m
Therefore, 8.16m is the required height.
Learn more about energy here:
brainly.com/question/1242059
#SPJ1
The distance from Buzău to Iaşi is 72 km. Find out the time a vehicle travels this distance if it has a speed of 72 km per hour. Expresses the speed in the unit of measurement in SI. I give the crown! Thank you
Answer:
3600seconds
Explanation:
Given parameters:
Distance = 72km
Speed = 72km/hr
Unknown:
Time it takes for the vehicle to travel the distance = ?
Solution:
Speed is the distance divided by time;
Speed = 
time =
Insert the parameters;
time =
= 1hr
The SI unit of time is in seconds;
3600 seconds is 1hr
The time is 3600seconds