wiz-icon
MyQuestionIcon
MyQuestionIcon
1
You visited us 1 times! Enjoying our articles? Unlock Full Access!
Question

A ball is projected perpendicularly from an inclined plane of inclination θ from horizontal, with velocity u as shown in figure. The time after which the projectile is making angle 45 with the inclined plane is


A
ugsinθ
No worries! We‘ve got your back. Try BYJU‘S free classes today!
B
ugcosθ
No worries! We‘ve got your back. Try BYJU‘S free classes today!
C
ug(sinθ+cosθ)
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
D
ug(sinθcosθ)
No worries! We‘ve got your back. Try BYJU‘S free classes today!
Open in App
Solution

The correct option is C ug(sinθ+cosθ)

Taking X & Y axis along the inclined plane and perpendicular to the inclined plane respectively as shown in figure.
ax=+gsinθ, ay=gcosθ,uy=+u, ux=0
At anytime t the component of velocity vector,
vx=ux+axt=0+gsinθ×t
vx=gsinθ t ...(i)
vy=uy+ayt=+ugcosθ×t
vy=ugcosθ t ...(ii)
At anytime t the angle (α) made by velocity vector from the Xaxis is given by:
tanα=vyvx
tanα=ugcosθ tgsinθ t
tan45=ugcosθ tgsinθ t
gsinθ t+gcosθ t=u

t=ug(sinθ+cosθ)

flag
Suggest Corrections
thumbs-up
4
Join BYJU'S Learning Program
similar_icon
Related Videos
thumbnail
lock
Solving n Dimensional Problems
PHYSICS
Watch in App
Join BYJU'S Learning Program
CrossIcon