I think it is D
Hope my answer help you?
Constant speed along the inclined surface = 30 m / 4 s = 7.5 m/s
Vertical speed = inclined speed * sin(45) = 7.5 *√2 / 2 = 5.3 m/s
Answer: 5.3 m/s
Complete Question
An airplane takes off a runway at a constant speed of 49 m/s at constant angle 30 to the horizontal.How high (in meters ) is the airplane above the ground 13 seconds after takeoff?
Answer:
The height is 
Explanation:
From the question we are told that
The speed at which the plane takes off is 
The angle at which it takes off is 
The time taken is 
The vertical distance traveled is mathematically represented as
Substituting values
'The normal is a line perpendicular to the surface of the mirror'.This is the correct statement that corrects an error on the site.
<h3>What is the law of reflection?</h3>
The law of reflection specifies that upon reflection from a downy surface, the slope of the reflected ray is similar to the slope of the incident ray.
The reflected ray is consistently in the plane determined by the incident ray and perpendicular to the surface at the point of reference of the incident ray.
When the light rays descend on the smooth surface, the angle of reflection is similar to the angle of incidence, also the incident ray, the reflected ray, and the normal to the surface all lie in a similar plane.
Hence 'The normal is a line perpendicular to the surface of the mirror'.This is the correct statement that corrects an error on the site
To learn more about the law of reflection refer to the link;
brainly.com/question/12029226
