Question

if an object thrown with 20m/s at 30° from horizontal , determine (1) time of flight (2) range of projectile (3) Hmax​

Answer 1

Answer:

Given that,

Speed u=20m/s

Angle θ=30

0

Height h=40m

Now, along y axis

u

y

=usin30

0

u

y

=20×

2

1

u

y

=10m/s

Now, we know that

a=−10m/s

2

s=−40m

Now, from equation of motion

s=u

y

t−

2

1

gt

2

−40=10t−5t

2

5t

2

−10t−40=0

t

2

−2t−8=0

t

2

−(4−2)t−8=0

t(t−4)+2(t−4)=0

(t+2)(t−4)

Now, neglect of negative value

So, t=4s

Now, the range is

R=ucos30

0

×t

R=20×

2

3

×4

R=40

3

m

Hence, the range is 40

3

m