Answer:
Option C
Explanation:
given,
velocity of airplane = 80 m/s
angle with the horizontal = 15°
speed of the ground= ?
when the plane is taking off the horizontal component of the velocity is v cosθ
so,
ground speed of the airplane is = 
= 
v = 77.27 m/s
horizontal velocity of the air plane comes out to be 77.27 m/s ≅ 77 m/s
so, the correct option is Option C
Answer:
Final velocity of NFL line backer is 16.67 m/s.
Explanation:
From the question, we have following data about the NFL line backer:
Initial Speed of line backer = Vi = 0 m/s (Since, he starts from rest)
Distance covered by NFL line backer = s = 100 m
Time taken by the NFL line backer to complete 100 m sprint = t = 12 s
Acceleration of NFL line backer during sprint = a
Final Velocity of NFL line backer = Vf = ?
First we need to find the acceleration of the NFL line backer. For that purpose we will use 2nd equation of motion:
s = (Vi)(t) + (0.5)at²
using values:
100 m = (0 m/s)(12 s) + (0.5)(a)(12 s)²
100 m/72 s² = a
a = 1.39 m/s²
Now, we use 1st equation of motion to find Vf:
Vf = Vi + at
Vf = 0 m/s + (1.39 m/s²)(12 s)
<u>Vf = 16.67 m/s</u>
Answer:
Explanation:
Kinetic energy can be found using the following formula.
where <em>m</em> is the mass and <em>v</em> is the velocity.
The mass of the toy plane is 20 kilograms and the velocity is 10 meters per second.
Substitute the values into the formula.
Solve the exponent first.
- (10 m/s)²= 10 m/s *10 m/s= 100 m²/s²
Multiply the last two numbers together.
Multiply by 1/2 or divide by 2.
- 1 kilogram square meter per square second is equal to 1 Joule.
- Our answer of 1000 kg*m²/s² is equal to 1000 Joules
The kinetic energy of the toy plane is <u>1000 Joules</u>
