Answer:
radiated heat from the Sun being absorbed by the ground
An open system can exchange both matter and energy with the surroundings. Δ H is measured when
an open system is used as a calorimeter.
A closed system has a fixed amount of matter, but it can exchange energy with the surroundings. Δ U is
measured when a closed system is used as a calorimeter because there is no change in volume and thus no
expansion work can be done.
An isolated system has no contact with its surroundings. The universe is considered an isolated system but on
a less profound scale, your thermos for keeping liquids hot approximates an isolated system.
Answer:
a) E = 7.57 10⁻⁵ N / C, b) B= 2.11 10⁻¹⁸ T, c) the magnitudes remain the same, but the sign of the responses change
Explanation:
a) The electric field due to a charged particle is
E = k q / r²
Let's look for the distance from the origin where the particle is to the point of interest
r² = (-3 10⁻³ -0)² + (-3 10⁻³ -0)²
r² = 19 10⁻⁶
The proton charge is
q = +1.6 10⁻¹⁹ C
Let's calculate
E = 8,988 10⁹ 1.6 10⁻¹⁹ / 19 10⁻⁶
E = 7.57 10⁻⁵ N / C
b) to calculate the magnetic field let's use the Biot-Savat law
B = μ₀/4π I / r²
The current is defined as the number of carriers per unit of time at a given point
I = q v
Let's calculate
B = 4π 10⁻⁷ /4π (1.6 10⁻¹⁹ 4 10⁴) / 19 10⁻⁶
B= 2.11 10⁻¹⁸ T
c) an electron has a charge of the same magnitude, but in the opposite direction, negative.
Therefore the magnitudes remain the same, but the senses (sign) of the responses change
The answer is fluid friction
Explanation:
Given that the first ball is thrown vertically and upward.
since it reaches the throwers hand after 3 seconds, then the time taken to reach maximum height is
= T/2
=3/2
=1.5 seconds
Also, the projection angle for the second ball is 30°
we know that at maximum height vertical velocity is 0
therefore the final velocity of the first ball is
Vy= 0
Also, since the first ball is thrown upward the horizontal velocity is 0
Vx=0
from the first law of motion
Vy=u+at
Vy=0, a= -g
Uy=gt
Uy=9.81*1.5
Uy=14.7m/s
since both reach the same height, they will have the same vertical velocity
Uy= Vo sin∅
Vo=Uy/sin∅
Vo= 14.7/sin 30
Vo=29.4m/s