Answer: Final speed will be 6.59 m/s
Explanation: Initial height of slide is 2.1 m
Final height = 0.7 m
Initial speed, u = 4 m/s
Final speed, v = ??
To find the final speed in this question we can use equation of motion i.e.

Here, S is the distance covered by the child on the slide i.e. net height
S = 2.1 - 0.7 = 1.4 m
and a = g, acceleration due to gravity i.e. 9.8 m/s
Put all the values in the equation,


= 16 + 27.44 = 43.44
Taking square root both the sides, we get
v = 6.59 m/s
Final speed will be 6.59 m/s
The answer is a <span>electrical energy is transformed into mechanical energy. </span>
Given parameters:
Volume of water in the tank = 750litres
Length of the tank = 150cm
Breadth of tank = 50cm
Unknown:
Height of the tank = ?
To solve this problem, we must understand the concept of volume. Volume is a property of solid bodies. It is mathematically derived as:
Volume = length x Breadth x height
The unknown here is the height and we should go ahead to solve for it.
<em>But the units are inconsistent. </em>
Therefore, convert litres to cm³;
1 litre = 1000cm³
750 litres = 1000 x 750 = 750,000cm³
Now input the parameters and solve for the height;
750000 = 150 x 50 x height
height =
= 100cm
Therefore, the height of the tank is 100cm
The helium may be treated as an ideal gas, so that
(p*V)/T =constant
where
p = pressure
V = volume
T = temperature.
Note that
7.5006 x 10⁻³ mm Hg = 1 Pa
1 L = 10⁻³ m³
Given:
At ground level,
p₁ = 752 mm Hg
= (752 mm Hg)/(7.5006 x 10⁻³ mm Hg/Pa)
= 1.0026 x 10⁵ Pa
V₁ = 9.47 x 10⁴ L = (9.47 x 10⁴ L)*(10⁻³ m³/L)
= 94.7 m³
T₁ = 27.8 °C = 27.8 + 273 K
= 300.8 K
At 36 km height,
P₂ = 73 mm Hg = 73/7.5006 x 10⁻³ Pa
= 9.7326 x 10³ Pa
T₂ = 235 K
If the volume at 36 km height is V₂, then
V₂ = (T₂/p₂)*(p₁/T₁)*V₁
= (235/9.7326 x 10³)*(1.0026 x 10⁵/300.8)*94.7
= 762.15 m³
Answer: 762.2 m³