Sayana Shakya

1.(c) w1 + w2

2.(b) the ground on the horse

3.(d) the road

4.(c) mg cosθ

5.(b) mg/cosθ

6.(d) remain standing

7.(a) zero

8.(a) F1 must be equal to F2

9.(b) A will go higher than B

10.(c) remain at the top of the wedge

11.(b) t1 > t2

12.(b) cannot be an inertial frame because the earth is

revolving around the sun

And

(d) cannot be an inertial frame because the earth is

rotating about its axis.

Solution

Given:

Height of balloon when stone was dropped (s)= -50 m/s [since the stone was dropped downwards]

Initial velocity (u) = 5.0 m/s

Acceleration due to gravity (a) =10 m/s²

Using formula,

s= ut + 1/2 * at²

-50 = 5t + 1/2 (-10)t²

-50 = 5t - 5t²

-50 = 5(t - t²)

-50/5 = t - t²

-10 = t - t²

t²- t - 10 = 0

t²- (3.7 - 2.7) t - 10 = 0

t²- 3.7 t + 2.7 t - 10= 0

( t - 3.7 ) ( t + 2.7 ) = 0

Either,

t = 3.7

or,

t = - 2.7

Since time ( t ) can never be negative,

t = 3.7 sec

Height of the balloon when stone hits the...