Answer:
The mass of the child + skateboard is 50 kg
Explanation:
In this problem, we can apply Newton's second law:
F = ma
where
F is the net force on a system
m is the mass of the system
a is the acceleration of the system
In this problem, our system is the child + the skateboard. The net force on them is
F = 75 N
and their acceleration is
So we can re-arrange the equation above to find their combined mass:
Answer:
The acceleration of the proton is 9.353 x 10⁸ m/s²
Explanation:
Given;
speed of the proton, u = 6.5 m/s
magnetic field strength, B = 1.5 T
The force of the proton is given by;
F = ma = qvB(sin90°)
ma = qvB
where;
m is mass of the proton, = 1.67 x 10⁻²⁷ kg
charge of the proton, q = 1.602 x 10⁻¹⁹ C
The acceleration of the proton is given by;
Therefore, the acceleration of the proton is 9.353 x 10⁸ m/s²
Answer:
The force is the same
Explanation:
The force per meter exerted between two wires carrying a current is given by the formula
where
is the vacuum permeability
is the current in the 1st wire
is the current in the 2nd wire
r is the separation between the wires
In this problem
Substituting, we find the force per unit length on the two wires:
However, the formula is the same for the two wires: this means that the force per meter exerted on the two wires is the same.
The same conclusion comes out from Newton's third law of motion, which states that when an object A exerts a force on an object B, then object B exerts an equal and opposite force on object A (action-reaction). If we apply the law to this situation, we see that the force exerted by wire 1 on wire 2 is the same as the force exerted by wire 2 on wire 1 (however the direction is opposite).