Gravity is pulling everything down . Without it, we all would be floating.
Answer:
Explanation:
At the submicroscopic and microscopic levels temperature is proportional to the average degree of kinetic energy of the particles of a substance
Answer:
x = 129.9 m
y = 30.9 m
Explanation:
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:
= 50 m/s
Angle = 30°
Time = t = 3 s
horizontal component of velocity =
=
cos30°
= 50cos30°
= 43.3 m/s
Vertical component of velocity =
=
Sin30°
= 50Sin30°
= 25 m/s
This is a projectile motion, 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.
But the vertical component of velocity varies with time and there is an acceleration along vertical direction which is equal to gravitational acceleration g.
Horizontal distance = x =
t
x = 43.3*3
x = 129.9 m
Vertical Distance = y =
t -0.5gt²
y = 25*3 - 0.5*9.8*3²
y = 75 - 44.1
y = 30.9 m
Answer:
a) Maximum height reached above ground = 2.8 m
b) When he reaches maximum height he is 2 m far from end of the ramp.
Explanation:
a) We have equation of motion v²=u²+2as
Considering vertical motion of skateboarder.
When he reaches maximum height,
u = 6.6sin58 = 5.6 m/s
a = -9.81 m/s²
v = 0 m/s
Substituting
0²=5.6² + 2 x -9.81 x s
s = 1.60 m
Height above ground = 1.2 + 1.6 = 2.8 m
b) We have equation of motion v= u+at
Considering vertical motion of skateboarder.
When he reaches maximum height,
u = 6.6sin58 = 5.6 m/s
a = -9.81 m/s²
v = 0 m/s
Substituting
0= 5.6 - 9.81 x t
t = 0.57s
Now considering horizontal motion of skateboarder.
We have equation of motion s =ut + 0.5 at²
u = 6.6cos58 = 3.50 m/s
a = 0 m/s²
t = 0.57
Substituting
s =3.5 x 0.57 + 0.5 x 0 x 0.57²
s = 2 m
When he reaches maximum height he is 2 m far from end of the ramp.
Answer:
Melting and frezzing are physical changes