Answer:
Yes
Explanation:
The plank (also called a front hold, hover, or abdominal bridge) is an isometric core strength exercise that involves maintaining a position similar to a push-up for the maximum possible time
Answer:
t = 1
Explanation:
you dont know the value of the variable
Answer:
Explanation:
Given that:
A circuit with a lagging 0.7 pf delivers 1500 watts and 2100VA
Here:
the initial power factor i.e cos θ₁ = 0.7 lag
θ₁ = cos⁻¹ (0.7)
θ₁ = 45.573°
Active power P = 1500 watts
Apparent power S = 2100 VA
What amount of vars must be added to bring the pf to 0.85
i.e the required power factor here is cos θ₂ = 0.85 lag
θ₂ = cos⁻¹ (0.85)
θ₂ = 31.788°
However; the initial reactive power 
= P×tanθ₁
the initial reactive power = 1500 × tan(45.573)
the initial reactive power = 1500 × 1.0202
the initial reactive power = 1530.3 vars
The amount of vars that must therefore be added to bring the pf to 0.85
can be calculated as:
Answer:
12.24 m/s
Explanation:
Speed: This can be defined as the rate of change of distance with time. The S.I unit of speed is m/s.
Using the formula,
a = v/t................ Equation 1
Where a = acceleration of the sprinter, v = speed of the sprinter, t = time.
making v the subject of the equation,
v = at ................. Equation 2
Given: a = 5.1 m/s², t = 2.4 s.
Substitute into equation 2
v = 5.1(2.4)
v = 12.24 m/s.
Hence, the speed of the sprinter = 12.24 m/s
Answer:
(a) 2800 J
(b) 31.28 %
Explanation:
Heat intake, Q1 = 8950 J
Heat discard, Q2 = 6150 J
(a) Work = intake heat energy - discarded heat energy
W = Q1 - Q2 = 8950 - 6150 = 2800 J
(b) Efficiency = 1 - Q2 / Q1
Efficiency = 1 - (6150 / 8950) = 0.3128 = 31.28%
