Answer:
The distance by the ball clear the crossbar is 1.15 m
Explanation:
Given that,
Distance = 44 m
Speed = 24 m/s
Angle = 31°
Height = 3.05 m
We need to calculate the horizontal velocity
Using formula of horizontal velocity

Put the value into the formula


We need to calculate the vertical velocity
Using formula of vertical velocity

Put the value into the formula


We need to calculate the time
Using formula of time

Put the value into the formula


We need to calculate the vertical height
Using equation of motion

Put the value into the formula


We need to calculate the distance by the ball clear the crossbar
Using formula for vertical distance

Put the value of h


Hence, The distance by the ball clear the crossbar is 1.15 m
Fluid Friction exists when it is acted upon an object when in fluid.
<span>net work = change in kinetic energy
for Block B, we just have the force from block A acting on it
F(ab)d= .5(1)vf² - .5(1)(2²)
F(ab)d= .5vf² - 2
Block A, we have the force from the hand going in one direction and the force of block B on A going the opposite direction
10-F(ba)d = .5(4)vf² - .5(4)(2²)
10-F(ba)d = 2vf² - 8
F(ba)d = 18 - 2vf²
now we have two equations:
F(ba)d = 18 - 2vf²
F(ab)d= .5vf² - 2
since the magnitude of F(ba) and F(ab) is the same, substitute and find vf (I already took into account the direction when solving for F(ab)
10-.5vf² + 2 = 2vf² - 8
12 - .5vf² = 2vf² - 8
20 = 2.5vf²
vf² = 8
they both will have the same velocity
KE of block A= .5(4)(2.828²) = 16 J
KE of block B=.5(1)(2.828²) = 4 J</span>
Answer:
Explanation:
Given ,
dv / dt = k ( 160 - v )
dv / ( 160 - v ) = kdt
ln ( 160 - v ) = kt + c , where c is a constant
when t = 0 , v = 0
Putting the values , we have
c = ln 160
ln ( 160 - v ) = kt + ln 160
ln ( 160 - v / 160 ) = kt
(160 - v ) / 160 = 
1 - v / 160 = 
v / 160 = 1 - 
v = 160 ( 1 -
)
differentiating ,
dv / dt = - 160k 
acceleration a = - 160k 
given when t = 0 , a = 280
280 = - 160 k
k = - 175
a = - 160 x - 175 
a = 28000 
when a = 128 t = ?
128 = 28000 
= .00457