Answer:
570 N
Explanation:
Draw a free body diagram on the rider. There are three forces: tension force 15° below the horizontal, drag force 30° above the horizontal, and weight downwards.
The rider is moving at constant speed, so acceleration is 0.
Sum of the forces in the x direction:
∑F = ma
F cos 30° - T cos 15° = 0
F = T cos 15° / cos 30°
Sum of the forces in the y direction:
∑F = ma
F sin 30° - W - T sin 15° = 0
W = F sin 30° - T sin 15°
Substituting:
W = (T cos 15° / cos 30°) sin 30° - T sin 15°
W = T cos 15° tan 30° - T sin 15°
W = T (cos 15° tan 30° - sin 15°)
Given T = 1900 N:
W = 1900 (cos 15° tan 30° - sin 15°)
W = 570 N
The rider weighs 570 N (which is about the same as 130 lb).
If you take 50 meters and divide by 23.1 seconds, you will get 2.16 meters per second.
So his average speed is 2.16 m/s.
Answer:
Approximately 
.
Explanation:
The formula for the kinetic energy 
of an object is:
,
where
is the mass of that object, and
is the speed of that object.
Important: Joule (
) is the standard unit for energy. The formula for requires two inputs: mass and speed. The standard unit of mass is 
while the standard unit for speed is 
. If both inputs are in standard units, then the output (kinetic energy) will also be in the standard unit (that is: joules,
Convert the unit of the arrow's mass to standard unit:
.
Initial of this arrow:
.
That's the same as the energy output of this bow. Hence, the efficiency of energy transfer will be:
.
The school that was supported was the Self psychology or the Ego psychology which is based on the model of the mind called id-ego-superego model
Answer:
just before landing the ground
Explanation:
Let the velocity of projection is u and the angle of projection is 30°.
Let T is the time of flight and R is the horizontal distance traveled. As there is no force acting in horizontal direction, so the horizontal velocity remains constant. Let the particle hits the ground with velocity v.
initial horizontal component of velocity, ux = u Cos 30
initial vertical component of velocity, uy = u Sin 30
Time of flight is given by
Final horizontal component of velocity, vx = ux = u Cos 30
Let vy is teh final vertical component of velocity.
Use first equation of motion
vy = uy - gT
vy = - u Sin 30
The magnitude of final velocity is given by
v = u
Thus, the velocity is same as it just reaches the ground.
