Answer
given,
mass of the ball = 3 kg
swing in vertical circle with radius = 2 m
work done by the gravity = ?
work done by the tension = ?
Work done by the gravity = - m g Δh
Δ h = 2 + 2 = 4 m
Work done by the gravity =
= -117.6 J
work done by gravity is equal to -117.6 J
Work done by tension will be equal to zero.
Zero because tension is always perpendicular to velocity
work done by tension is equal to 0 J
Answer:
(a). The reactive power is 799.99 KVAR.
(c). The reactive power of a capacitor to be connected across the load to raise the power factor to 0.95 is 790.05 KVAR.
Explanation:
Given that,
Power factor = 0.6
Power = 600 kVA
(a). We need to calculate the reactive power
Using formula of reactive power
...(I)
We need to calculate the 
Using formula of 

Put the value into the formula


Put the value of Φ in equation (I)


(b). We draw the power triangle
(c). We need to calculate the reactive power of a capacitor to be connected across the load to raise the power factor to 0.95
Using formula of reactive power


We need to calculate the difference between Q and Q'

Put the value into the formula


Hence, (a). The reactive power is 799.99 KVAR.
(c). The reactive power of a capacitor to be connected across the load to raise the power factor to 0.95 is 790.05 KVAR.
Answer:
= 7.07 m
Explanation:
The Tarzan reaches bottom of swing after descending 2.5 m,
change in his potential energy equals his kinetic energy at bottom of swing
m g h = (1/2) m v² ,
hence speed v of Tarzan at bottom of swing is given as
v = ( 2 g h )1/2
= ( 2 × 9.8 × 2.5 )1/2
= 7 m/s
At the bottom of swing, if the vine breaks, then he is moving with horizontal velocity 7 m/s in gravitational field.
If vertical distance from ground to bottom of swing is 5 m, then time t for Tarzan to reach ground is given by
S = (1/2)g t2 or t = (2S/g)1/2
= ( 2 × 5 / 9.8 )1/2
= 1.01 s
Horizontal distance traveled by Tarzan = 1.01 × 7
= 7.07 m
Answer: 4
Explanation: speed= distance/time