Answer:
0.833
Explanation:
Power = energy / time
Power = force × distance / time
Power = force × velocity
P = (850 kg) (9.8 m/s²) (1.00 m/s)
P = 8330 W
P = 8.33 kW
The efficiency of the motor is therefore:
e = 8.33 kW / 10.0 kW
e = 0.833
In vertical motion the arrow will be accelerating so we can use equation of motion
but first we need to find initial vertical and horizontal velocity
Horizontal velocity
cos65=x( horizontal)/20
x=8.45m/s
Thus now we can calculate time after which it strike the wall
8.45=10/t
t=1.18 s this speed in horizontal will remain constant
vertical intial velocity
sin65=y(vertical)/20
y=18.13 m/s
use the equation of motion to calculate height
s=ut+1/2 at^2
s=(18.13)(1.18)+ 1/2 (-9.8)(1.18^2)
s=21.40-6.822
s=14.58 m
but as it is already 1.80 above ground
So
The height of wall be =14.58+1.80=16.38m
ANSWER 16.38 meters
Answer:
1)49m/s
2)122.5m
Explanation:
The expression below can be use to calculate the initial velocity from law of motion
V2 - V1= at
Where V2= final velocity
V1= initial velocity( from rest)
a=acceleration
t= time= 5 seconds
But V2=0
V1=gt
Where g= acceleration due to gravity= 9.8m/s^2
V1= 9.8×5
V1=49m/s
Then we can now calculate the maximum height the rocket reaches by using below formula
V^2=2gh
h(max)=v^2/2g
Where h= maximum height
V2= initial velocity
=49^2/(2×9.8)
=2401/19.6
=122.5m
Hence the maximum height it reaches vis 122.5m
Answer:
Explanation:
given,
mean of hospital waiting (μ) = 38.12 min
standard deviation (σ) = 8.63 min
worst waiting time = 20%
the are will be same as the = 100 - 20%
= 80%
we have to determine the z- value according to 80% or 0.80
using z-table
z-value = 0.85
now, using formula
Nebulas, because nebulas contain the gas needed to form a star and comets/planets/ asteroids are rocks not gas