Answer:
b= 2.14 m
Explanation:
Given that
Weight of the board ,wt = 40 N
Wight of the first children , wt₁=500 N
Weight of the second children ,wt₂ = 350 N
The distance of the 500 N child from center ,a= 1.5 m
lets take distance of the 350 N child from center = b m
Now by taking the moment about the center of the board
We know that moment = Force x Perpendicular distance from the force
wt₁ x a = wt₂ x b
500 x 1.5 = 350 x b
b= 2.14 m
Therefore the distance of the 350 N weight child from the center is 2.14 m.
Answer:
2.13 s
Explanation:
Hi!
At t = 0s the rocket is at rest in its platform, so the intial speed is zero. I f the acceleration is A, then the height Y, and the speed V are:
We nedd to find time T during which the rocket engine provides upward acceleration. We know that:
With these 2 equations we can find A and T (dropping units for simplicity):
Explanation & answer:
Given:
Fuel consumption, C = 22 L/h
Specific gravity = 0.8
output power, P = 55 kW
heating value, H = 44,000 kJ/kg
Solution:
Calculate energy intake
E = C*P*H
= (22 L/h) / (3600 s/h) * (1000 mL/L) * (0.8 g/mL) * (44000 kJ/kg)
= (22/3600)*1000*0.8*44000 j/s
= 215111.1 j/s
Calculate output power
P = 55 kW
= 55000 j/s
Efficiency
= output / input
= P/E
=55000 / 215111.1
= 0.2557
= 25.6% to 1 decimal place.
Answer:
Explanation:
Position of charge q₁ is (0,0)
Position of charge q₂ is (x₁,0)
So, the electric potential energy between the charges is given by :
Now the position of charge q₂ has been changes from (x₁,0) to (x₂,y₂). Now, electric potential energy between the charges is :
We know form the work energy theorem that, the change in potential energy is equal to the work done. Mathematically, it is given by :
Hence, the work done by the electrostatic force on the moving point charge is 
. Hence, this is the required solution.
4. Table 2.4 shows how the displacement of a runner changed
during a sprint race. Draw a displacement–time graph to show
this data, and use it to deduce the runner’s speed in the middle
of the race.
Table 2.4 Data for a sprinter during a race
Displacement
(m)
0 4 10 20 50 80 105
Time (s) 1 2 3 6 9 12
