Answer:

Explanation:
Given,
Magnetic field, B = 5 x 10⁻⁵ T
Number of turns, N = 450
length = 29 cm
Current,I = ?
Using formula of magnetic field due to solenoid




Hence, the current obtained is equal to 0.0256 A.
Answer:
Distance, d = 112.5 meters
Explanation:
Initially, the bicyclist is at rest, u = 0
Final speed of the bicyclist, v = 30 m/s
Acceleration of the bicycle, 
Let s is the distance travelled by the bicyclist. The third equation of motion is given as :



s = 112.5 meters
So, the distance travelled by the bicyclist is 112.5 meters. Hence, this is the required solution.
Answer:
the speed of the center of mass stays the same
Explanation:
In a system with no energy loss, momentum is conserved if the mass remains constant. The system described has no change in mass, and energy loss is considered negligible. Hence the product of the total mass and the velocity of its center will be a constant. The center of mass stays the same speed.
Answer:
B
Explanation:
You always want to test as many samples as possible