Explanation:
Let the speeds of father and son are 
. The kinetic energies of father and son are 
. The mass of father and son are 
(a) According to given conditions, 
And 
Kinetic energy of father is given by :
.............(1)
Kinetic energy of son is given by :
...........(2)
From equation (1), (2) we get :
..............(3)
If the speed of father is speed up by 1.5 m/s, so the ratio of kinetic energies is given by :
Using equation (3) in above equation, we get :
(b) Put the value of 
in equation (3) as :
Hence, this is the required solution.
Answer:
1.67m/s
Explanation:
Total Distance to be travelled by a Runner=100m
Time Taken=10*6s
Speed=Distance/Time
=100/10*6=10/6=1.67m/s
Answer:
13 N
Explanation:
The Net Force of an object should be the difference between the forces applied to the object if the object is not in equilibrium. This object is not in equilibrium so therefore by finding the difference between the forces, you will find your answer. 20 N - 7 N = 13 N.
Answer:
8.1 N/49 N=0.1653 which means 16.53% of the weight of the object on Earth.
Explanation:
On the Moon, where the gravitational constant is 1.62 
, the weight of the 5 kg object will be: 
Where the answer is in Newtons (N) since all quantities are given in the SI system.
On Earth, on the other hand, the weight of the object is:
Therefore the object's weight on the Moon compared to that on Earth will be:
That is, 16.53% of the weight the object has on Earth.
Answer:
Explanation:
Given:
- mass of rocket,
- time of observation,
- mass lost by the rocket by expulsion of air,
- velocity of air,
<u>Now the momentum of air will be equal to the momentum of rocket in the opposite direction: </u>(Using the theory of elastic collision)
