"Fig is attacted with answer"
Answer:
a) d = 33.72 m
b)
= 26 m/s
c) β = 71.08°
Explanation:
a)
When an object is thrown into the air under the effect of the gravitational force, the movement of the projectile is observed. Then it can be considered as two separate motions, horizontal motion and vertical motion. Both motions are different, so that they can be handled independently.
Given data:
time = t = 4.00 s
Height = h = 20 m
Angle = θ = 60°
Horizontal distance = d = ?
Using 2nd equation of motion

-20 =
(4) + 0.5(-9.8)(4)²
(4) = 58.4
= 14.6 m/s
This is vertical component of velocity when the ball is on the roof. To calculate the Final velocity and horizontal component, we use
=
/ sinθ
= 14.6 / sin 60
= 16.86 m/s
=
cosθ
= 16.86 cos 60
= 8.43 m/s
To calculate the horizontal distance
d =
t
d = (8.43)(4)
d = 33.72 m
b)
We know the values of Landing angle, height of roof, time of flight. In part a, We calculate the landing velocity of the ball and also its horizontal and vertical component. As the ball followed the projectile path, and we know that in projectile motion the horizontal component of the velocity remain constant throughout his motion. So there is no acceleration along horizontal path.
So,
= 
but the vertical component of velocity vary with and there is an acceleration along vertical direction which is equal to gravitation acceleration g.
So,
g = (
-
) / t
9.8 = 14.6 -
) / 4
= 24.6 m/s
= 
= 
= 26 m/s
c)
cos β =
/ 
β = cos⁻¹ (8.43 / 26)
β = 71.08°
We know that speed is a scalar unit while velocity is a vector. The signs are mostly concerned with the magnitude that the car should travel in, the direction is not as important.
Hope I helped :)
|Momentum| = (mass) x (speed)
225 kg-m/s =(50kg) x (speed)
Divide each side by (50kg): Speed=(225 kg-m/s) / (50 kg) = 4.5 m/s .
Regarding the velocity, nothing can be said other than the speed, because
we have no information regarding the direction of the object's motion.
Answer:
a) The back spoon gives a right image (upright)
b) the front gives an inverted image
Explanation:
The spoon is a curved metallic object, when we see ourselves from the back we have a convex mirror, in this type of mirror when the law of reflection is applied the rays diverge therefore the eye-brain system forms the image with the prolongation of the rays, therefore the image is straight and smaller than the object.
When we look through the deep side of the spoon, we have a concave mirror and as the object (we) is further away than the distance, the rays converge to a point, so the image is real, inverted smaller than the object.
In summary.
a) The back spoon gives a right image (upright)
b) the front gives an inverted image