Answer:
A) 
B) 
Explanation:
A) In this situation we are talking about a car moving only in the X- axis, hence the velocity of the car is:

Where the unit vectors
,
and
represent the components
,
and
in the cartesian plane.
In this sense, each unit vector is defined to have a magnitude of exactly one (1).
B) Velocity is defined as the variation of position in time, if this car is moving only along the x direction we will have:

Clearing the position:



Answer:
Final velocity of the block = 2.40 m/s east.
Explanation:
Here momentum is conserved.
Initial momentum = Final momentum
Mass of bullet = 0.0140 kg
Consider east as positive.
Initial velocity of bullet = 205 m/s
Mass of Block = 1.8 kg
Initial velocity of block = 0 m/s
Initial momentum = 0.014 x 205 + 1.8 x 0 = 2.87 kg m/s
Final velocity of bullet = -103 m/s
We need to find final velocity of the block( u )
Final momentum = 0.014 x -103+ 1.8 x u = -1.442 + 1.8 u
We have
2.87 = -1.442 + 1.8 u
u = 2.40 m/s
Final velocity of the block = 2.40 m/s east.
Answer:
a) When its length is 23 cm, the elastic potential energy of the spring is
0.18 J
b) When the stretched length doubles, the potential energy increases by a factor of four to 0.72 J
Explanation:
Hi there!
a) The elastic potential energy (EPE) is calculated using the following equation:
EPE = 1/2 · k · x²
Where:
k = spring constant.
x = stretched lenght.
Let´s calculate the elastic potential energy of the spring when it is stretched 3 cm (0.03 m).
First, let´s convert the spring constant units into N/m:
4 N/cm · 100 cm/m = 400 N/m
EPE = 1/2 · 400 N/m · (0.03 m)²
EPE = 0.18 J
When its length is 23 cm, the elastic potential energy of the spring is 0.18 J
b) Now let´s calculate the elastic potential energy when the spring is stretched 0.06 m:
EPE = 1/2 · 400 N/m · (0.06 m)²
EPE = 0.72 J
When the stretched length doubles, the potential energy increases by a factor of four to 0.72 J
Answer:
(a) Magnetic moment will be 
(b) Torque will be 
Explanation:
We have given dimension of the rectangular 5.4 cm × 8.5 cm
So area of the rectangular coil 
Current is given as 
Number of turns N = 25
(A) We know that magnetic moment is given by 
(b) Magnetic field is given as B = 0.350 T
We know that torque is given by 
Answer:
Torque τ =w ×0 = 0
Explanation:
We know that the torque is given by the product of the force and perpendicular distance between the force and the axis.
Here the gravity force act at the center and the rotational axis is also passing through the center.
Therefore the perpendicular distance between the force and the rotational axis would be zero.
Hence the torque will be
Torque = Force × Perpendicular distance
Torque = mg×0 = 0
Therefore the torque would be zero.