Since his line of sight 63 degrees makes with the tip of the building
Tan63° = height of building / Horizontal distance
tan63° = Height / 50
50tan63° = Height
Height = 50tan63°
Height ≈ 50*1.9626
Height ≈ 98.13 m
Height of the building is ≈ 98.13 m. Mind you in solving for this height we have neglected the height of Daniel.
The height of building actually should be 98.13 m plus the height of Daniel. Since the 63° was measured from his eye level.
Answer: The same current flows through bth cables
Explanation:
Lets have a look to the next two equations
The Ohm´s V = I*R (1)
where:
V is voltage (potencial dfference) in volts
I is the electric current in ampers
R is the electric resistance
When a voltage is applied as the electrc load is not specified ( we have to assume is the same) the current will be the same
And in the other hand the resistance R =ρL/s
Where ρ is the resistivity of the conductor L the length and s square section of the conductor
If we assume that the smaller diameter cable is able to conduct the current then nothing happens. The point is that the capacity of conduction of current depend on the section of the cable (the area)
Tables exist where to find the capacity of each cable according to its diameter.
I think it might be heat energy. light transforms into heat energy
Initial speed, u = 15 m/s
Final speed, v = 10 m/s
Distance traveled, s = 6.0 m
The acceleration, a, is determined from
u² + 2as = v²
(15 m/s)² + 2*(a m/s²)*(6.0 m) = (10 m/s)²
225 + 12a = 100
12a = -125
a = -10.4167 m/s²
The time, t, for the velocity to change from 15 m/s to 10 m/s is given by
(10 m/s) = (15 m/s) - (10.4167 m/s²)*(t s)
10 = 15 - 10.4167t
t = 0.48 s
The average speed is
(6.0 m)/(0.48 s) = 12.5 m/s
Answer: 12.5 m/s
Answer
Hi,
correct answer is {D} 3.5 m/s²
Explanation
Acceleration is the rate of change of velocity with time. Acceleration can occur when a moving body is speeding up, slowing down or changing direction.
Acceleration is calculated by the equation =change in velocity/change in time
a= {velocity final-velocity initial}/(change in time)
a=v-u/Δt
The units for acceleration is meters per second square m/s²
In this example, initial velocity =2.0m/s⇒u
Final velocity=44.0m/s⇒v
Time taken for change in velocity=12 s⇒Δt
a= (44-2)/12 = 42/12
3.5 m/s²
Best Wishes!
