First, you try to make sure that both the denominators are the same. In order to do this, you multiply both fractions' numerator and denominator by the other fraction's denominator. Next, you combine like terms in the numerator, and then you simplify the fraction.
1/2*(-1/7) = - (1*1)/(2*7)= - 1/14
(+)*(-) = (-)
Answer : - 1/14
Answer:
20 sets
Step-by-step explanation:
320/16=20
He needs 320 ping pong balls, and he has 16, so divide the amount needed by the amount that comes in each containter.
<span> You have :
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v0 = 35 m/s
B = angle of elevation = 30 deg
a suby = - g
v suby0 = ( v0 ) ( sin B )
v suby0 = ( 35 m/s ) ( sin 30 ) = 17.5 m/s
At maximum height :
------------------------------
v suby = vy* = 0.0
t = t*
y = ymax = y*
Basic kinematics gives :
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a suby = dv suby / dt = -g ------> dt = dv suby /a suby
v suby = dy/dt ------> dt = dy / vsuby
dt = dv suby / a suby = dy / v suby
( v suby ) ( d v suby) = ( a suby ) dy = ( -g ) dy
Now integrate and get :
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( v suby* )^2 - ( v suby0)^2 ( 1/2 ) = ( -g ) ( ymax )
ymax = [ ( v suby0 )^2 - ( v suby* )^2 ] / [ ( 2 ) ( g ) ]
ymax = ( 17.5 m/s )^2 - ( 0.0 m/s )^2 ] / [ ( 2 ) ( 9.807 m/s^2 ) ]
ymax = 15.6 m <------------------
Check the result:
--------------------------
t* = v suby0 / g = ( 17.5 m/s ) / ( 9.807 m/s^2 ) = 1.784 s
y* - y0 = ( v suby0 ) ( t* ) - ( g/2 ) ( t* )^2
y* = ( 17.5 m/s ) ( 1.784 s ) - ( 9.807 m/s^2 / 2 ) ( 1.784 s )^2
y* = ymax = 31.23 m - 15.61 m = 15.6 m
The ymax values agree.</span>
