Answer:
= 1.75 × 10⁻⁴ m/s
Explanation:
Given:
Density of copper, ρ = 8.93 g/cm³
mass, M = 63.5 g/mol
Radius of wire = 0.625 mm
Current, I = 3A
Area of the wire,
=
Now,
The current density, J is given as
= 2444619.925 A/mm²
now, the electron density, 
where,
=Avogadro's Number

Now,
the drift velocity, 

where,
e = charge on electron = 1.6 × 10⁻¹⁹ C
thus,
= 1.75 × 10⁻⁴ m/s
Answer:
Explanation:
Given
Initial speed 
distance traveled before coming to rest 
using equation of motion

where v=final velocity
u=initial velocity
a=acceleration
s=displacement

for 
using same relation we get

divide 1 and 2 we get


So a distance if 213.32 ft is required to stop the vehicle with 80 mph speed
Answer: 
Explanation:
Given
mass of ball m=10 kg
It is placed at a height of 150 m
It is dropped from the height and allowed to free fall for 40 m
Velocity acquired by the ball during this fall is given by 
Insert u=0, a=g

Kinetic energy at this instant

Answer:
2000 kg m/s
Explanation:
The momentum of an object is a vector quantity whose magnitude is given by

where
m is the mass of the object
v is the velocity of the object
and its direction is the same as the velocity.
In this problem, we have:
- Spaceship 1 has
m = 200 kg (mass)
v = 0 m/s (zero velocity)
So its momentum is

- Spaceship 2 has
m = 200 kg (mass)
v = 10 m/s (velocity)
So its momentum is

Therefore, the combined momentum of the two spaceships is

Answer:
A
Explanation:
An object in motion will stay in motion unless acted upon by an external force.
Say you rolled a ball on the ground, eventually it will stop because of friction and gravity