Answer:
Vr = 3.24m/s
The boat is going 3.24m/s relative to the bank of the river.
Explanation:
The relative speed of the boat to the bank Vr is the resultant of speed of boat relative to the water Vb and the speed of boat as a result of the water current or wind Vw
Vr = √(Vb^2 + Vw^2) .....1
Given;
Vb = 2.6m/s
Vw = distance downstream/time = 690m/355s
Vw = 1.94m/s
From equation 1 above; substituting the values
Vr = √(2.6^2 + 1.94^2)
Vr = 3.24m/s
The boat is going 3.24m/s relative to the bank of the river.
Answer:

Explanation:
The electrostatic force between the proton and the electron is given by:

where
is the Coulomb constant
is the magnitude of the charge of the proton
is the magnitude of the charge of the electron
is the distance between the proton and the electrons
Substituting the values into the formula, we find

The correct option is A) work.
Work is said to be done by a force when a force is exerted on an object and the the object on which the force is exerted moves in the direction of the force.
The amount of work done is given by the product of the force and the displacement made by the object.
Option (B) is incorrect, since Watt is the unit of power.
Option (C) is wrong, since joule is the unit of work or energy.
Option (D) is wrong, since power is the rate at which work is done.
Answer:

24.21 m/s
Explanation:
x = Displacement in x direction = 55 m
y = Displacement in x direction = 0
= Height of the ball when the ball is kicked = 1 m
t = Time taken = 4.2 s
= Acceleration due to gravity = 
u = Initial velocity of ball
Displacement in x direction is given by

Displacement in y direction is given by


The ball should be kicked at an angle of 

The initial speed of the ball is 24.21 m/s.
Answer:
The magnitude of the magnetic field made by current in the wire is 3.064 x 10⁻⁶ T.
Explanation:
Given;
length of the straight wire, L = 0.56 m
conventional current, I = 0.4 A
distance of magnetic field from the wire, r = 2.6 cm = 0.026 m
To determine magnitude of magnetic field made by current in the wire, we will apply Bio-Savart Law;

Therefore, the magnitude of the magnetic field made by current in the wire is 3.064 x 10⁻⁶ T.