A man is travelling at 10.8 km/h in a topless car on a rainy day. He holds an umbrella at an angle 370 to the vertical to protect himself from the rain which is falling vertically downwards. What is the velocity of the rain in m/s. (Given cos 370 = 4/5)
Answers
Given: A man is travelling at 10.8 km/h in a topless car on a rainy day. He holds an umbrella at an angle 37 degree to the vertical to protect himself from the rain which is falling vertically downwards.
To find: The velocity of the rain in m/s.
Solution:
- Now we have given that he holds an umbrella at an angle 37 degree to the vertical to protect himself from the rain which is falling vertically downwards.
v(m) = 10.8 km/h
= 10.8 x 5/18
v(m) = 3 m/s
- Now tan Ф = v(m) / v(r)
v(r) = v(m) / tan Ф
v(r) = 3 / tan (37)
v(r) = 3 / (3/4)
v(r) = 4 m/s
Answer:
The velocity of the rain is 4 m/s.
Explanation:
Given A man is travelling at 10.8 km/h in a topless car on a rainy day. He holds an umbrella at an angle 370 to the vertical to protect himself from the rain which is falling vertically downwards. What is the velocity of the rain in m/s.
- So Vm = 10.8 km / h
- Now the vertical is at 37 degree
- Now the velocity of rain is vertically downwards
- We need to find the velocity of the rain.
- So it will be velocity of rain with respect to man.
- Velocity of rain w.r.t man = velocity of rain – velocity of man
- So a triangle with 37 degree is formed.
- So we have tan 37 = 3/4
- So 3/4 = perpendicular / base
- So 3/4 = 10.8 / velocity of rain
- So velocity of rain = 4/3 x 10.8
- = 4/3 x 10.8 x 1000 / 60 x 60
- = 4/3 x 108 / 36
- = 4 m/s
Reference link will be
https://brainly.in/question/18454590