A projectile shot at an angle of 45 above the horizontal strikes a building 30 m away at a
point 15 m above the point of projection. Find :
(a) the speed of projection
(b) the magnitude and direction of velocity of projectile when it strikes the building. (Take g = 9.8 m/s2
Asked by gargpuneet989
10th August 2018,
7:47 PM
Answered by Expert
Answer:
Projectile equation is given by, 
where x an y are horizontal and vertical coordinates in projectile trajectory
when the point of projection is taken as origin. U0 and θ0 are velocity and angle of projection respectively.
if we substitue x=30, y=15, θ0=45 in eqn.(1), we get u0 = 14√3 m/s
To get the magnitude and direction of velocity, we use the formula, " v2 = u2 - 2gh " ,
where v is the vertical component of velocity at the striking point, u is the initial vertical component of velocity
and h is the vertical height.
hence, v2 = (14√3×sin45)2 - 2×9.8×15 = 0 or v=0
Hence at striking point, we have only horizontal component of projectile velocity, i.e., 14√3×cos45 = 17.15 m/s.
direction is horizontal.
Answered by Expert
11th August 2018,
12:11 PM
Rate this answer
- 1
- 2
- 3
- 4
- 5
- 6
- 7
- 8
- 9
- 10
You have rated this answer /10
Your answer has been posted successfully!
RELATED STUDY RESOURCES :
Browse free questions and answers by Chapters
- 1 Thermodynamics
- 2 Gravitation
- 3 Electromagnetic Waves
- 4 Communication Systems
- 5 Laws of Motion
- 6 Current Electricity
- 7 Work, Energy and Power
- 8 Kinematics
- 9 Physics and Measurement
- 10 Rotational Motion
- 11 Properties of Solids and Liquids
- 12 Kinetic Theory of Gases
- 13 Oscillations and Waves
- 14 Electrostatics
- 15 Magnetic Effects of Current and Magnetism
- 16 Electromagnetic Induction and Alternating Currents
- 17 Optics
- 18 Dual Nature of Matter and Radiation
- 19 Atoms and Nuclei
- 20 Electronic Devices
Trending Tags
Latest Questions
JEE Main Mathematics
Asked by amaladelsingh
28th October 2020,
10:24 PM
CBSE X Biology
Asked by reenacharan2008
28th October 2020,
9:11 PM
