Convection, the matter is traveling in convection currents
Answer:
The magnetic field inside the solenoid would decrease by a factor of 2.
Explanation:
The magnetic field, B, of a solenoid of length L, N windings, and radius b with a current, I, flowing through it is given as:
B = (N * r * I) / L
If the length of the solenoid is doubled, 2L,the magnetic field becomes:
B2 = (N * r * I) / 2L
B2 = ½ B
The magnetic field will decrease by a factor of 2.
Answer:
d. 3332.5 [N]
Explanation:
To solve this problem we will use newton's second law, which tells us that the sum of forces is equal to the product of mass by acceleration.
Here we have two forces, the force that pushes the car to move forward and the friction force.
The friction force is equal to the product of the normal force by the coefficient of friction.
f = N * μ
f = (m*g) * μ
where:
N = weight of the car = 2150*9.81 = 21091.5 [N]
μ = 0.25
f = (21091.5) * 0.25
f = 5273 [N]
Now as the car is moving forward, the car wheels move clockwise. The friction force between the wheels of the car and the pavement must be counterclockwise, i.e. counterclockwise. Therefore the direction of this force is forward. This way we have:
F + f = m*a
F + 5273 = 2150*4
F = 8600 - 5273
F = 3327 [N]
Therefore the answer is d.
Answer:
Approximately 
(rounded down,) assuming that 
.
The number of repetitions would increase if efficiency increases.
Explanation:
Ensure that all quantities involved are in standard units:
Energy from the cookie (should be in joules, 
):
.
Height of the weight (should be in meters, 
):
.
Energy required to lift the weight by 
without acceleration:
.
At an efficiency of 
, the actual amount of energy required to raise this weight to that height would be:
.
Divide 
by 
to find the number of times this weight could be lifted up within that energy budget:
.
Increasing the efficiency (the denominator) would reduce the amount of energy input required to achieve the same amount of useful work. Thus, the same energy budget would allow this weight to be lifted up for more times.
Answer:
Explanation: relationship between the object and the observer's frame of reference.
