Answer:
Vf= 7.29 m/s
Explanation:
Two force act on the object:
1) Gravity
2) Air resistance
Upward motion:
Initial velocity = Vi= 10 m/s
Final velocity = Vf= 0 m/s
Gravity acting downward = g = -9.8 m/s²
Air resistance acting downward = a₁ = - 3 m/s²
Net acceleration = a = -(g + a₁ ) = - ( 9.8 + 3 ) = - 12.8 m/s²
( Acceleration is consider negative if it is in opposite direction of velocity )
Now
2as = Vf² - Vi²
⇒ 2 * (-12.8) *s = 0 - 10²
⇒-25.6 *s = -100
⇒ s = 100/ 25.6
⇒ s = 3.9 m
Downward motion:
Vi= 0 m/s
s = 3.9 m
Gravity acting downward = g = 9.8 m/s²
Air resistance acting upward = a₁ = - 3 m/s²
Net acceleration = a = g - a₁ = 9.8 - 3 = 6.8 m/s²
Now
2as = Vf² - Vi²
⇒ 2 * 6.8 * 3.9 = Vf² - 0
⇒ Vf² = 53. 125
⇒ Vf= 7.29 m/s
The answer to this question is c
"lets exercise and eat healthy foods together"<span />
Answer:
Object A and C (Second choice)
Let's observe one by one
#A..
Kupier belt is a belt associated at Neptune outerside similar to asteroid belt
#B.
Has enough gravity to keep other objects far away from its orbit
- It's any planet or may be sun /star
No
#C
Is in orbit around the sun
#D
Is almost circular in shape
Because force always has a direction, it always works towards or against something.
you might know that force,
is rate of change of momentum i.e
force = m (v-u)/t
= (mv - mu )/ t
as we know momentum is a vector quantity so, the rate of change of momentum i.e Force would also be a vector quantity.
momentum = mass × velocity
velocity has a direction so,
momentum has also got a direction.
so, momentum is also a vector quantity.
