Answer:
Explanation:
mass of car, m = 1000 kg
initial velocity, u = 20 m/s
final velocity, v = 0 m/s
distance, s = 120 m
Let a be the acceleration of motion
use third equation of motion
v² = u² + 2 as
0 = 20 x 20 + 2 x a x 120
a = - 1.67 m/s²
Let F be the force
Force, F mass x acceleration
F = - 1000 x 1.67
F = - 1666.67 N
The direction of force is towards south and the magnitude of force is 1666.67 N.
Answer:
rise the air temperature is 0.179241 K
Explanation:
Given data
mass = 20000 kg
velocity = 18.5 m/s
long = 65 m
wide = 20 m
height = 12 m
density of the air = 1.20 kg/ m³
specific heat = 1020 J/(kg*K)
to find out
how much does the air temperature in the station rise
solution
we know here Energy lost by the train that is calculated by
loss in the kinetic energy that is = 1/2 m v²
loss in the kinetic energy = 0.5 × 20000 ×18.5²
loss in the kinetic energy is 3422500 J
and
this energy is used here to rise the air temperature that is KE / ( specific hat × mass )
so here
air volume = 65 ×20×12
air volume = 15600 m³
air mass = ρ × V = 1.2 × 15600
air mass = 18720 kg
so
rise the air temperature = 3422500 / ( 1020 × 18720)
rise the air temperature is 0.179241 K
surface wave is a wave that travels along the surface of a medium. The medium is the matter through which the wave travels. Ocean waves are the best-known examples of surface waves. They travel on the surface of the water between the ocean and the air.
HOPE IT HELPS
Answer:
We show added energy to a system as +Q or -W
Explanation:
The first law of thermodynamics states that, in an isolated system, energy can neither be created nor be destroyed;
Energy is added to the internal energy of a system as either work energy or heat energy as follows;
ΔU = Q - W
Therefore, when energy is added as heat energy to a system, we show the energy as positive Q (+Q), when energy is added to the system in the form of work, we show the energy as minus W (-W).
Acceleration is a change in velocity, either an increase in speed or a change in direction. Acceleration measures the rate of change of an object's velocity. Average acceleration is calculated by dividing the change in velocity over the time.