1.
Answer:
a) It is less
Explanation:
By energy conservation we can say that initial potential energy of both child must be equal to the final kinetic energy of the two child.
Since initially they are at same height so we will say that initial potential energy will be given as
and MgH
so the child with greater mass has more energy and hence smaller child will reach with smaller kinetic energy
2.
Answer:
b. The two speeds are equal.
Explanation:
As we know by mechanical energy conservation law we have


since both child starts at same height so here they both will reach the bottom at same speed
3.
Answer:
c. The two accelerations are equal
Explanation:
Since we know that average acceleration of the motion is given as

since here initial and final speeds are same so they both must have same average acceleration here.
Answer:

Explanation:
Here we know that the glider is accelerated uniformly from rest to final speed of 25.7 m/s in total distance of d = 46.9 m
so we will have


d = 46.9
so for uniformly accelerated motion we have



now we will find the total work done given as change in kinetic energy



now power is given as



We will convert the 1dm3 in terms of cm3 as follows:
1dm^3 = (10 cm)^3
= 1000 cm^3
The mass of platinum is equal to 900 lb.
Then we will convert the mass in terms of grams as follows:
1 lb = 453.6 g
900 = 900 x 453.6 g
= 408240 g
Then density of platinum is equal to 21.4 g/cm^3
We will calculate the volume of platinum in mass 408240 g as follows:
Volume of platinum = mass of platinum / density of platinum
= 408240 g / 21.4 g/cm^3
= 19076.6 cm^3
The total volume of platinum is 19076.6 cm^3
The volume of platinum in 1 L bar is 1000cm^3
So, to calculate the number of bars we will use the formula as follows;
Number of bars = volume of platinum available / volume of platinum required in 1 L bar
= 19076.6 cm^3 / 1000 cm^3
= 19
So, the number of bars are 19.