Question

7
has B travelled by the time it passes C?
A ball is gently dropped from a height of 20 m. If its velocity
increases uniformly at the rate of 10 m s2, with what velocity
will it strike the ground? After what time will it strike the
ground?
The speed-time graph for a car is shown is Fig. 8.12.
8.
8
s )
Speed (ms
8 10
2 4 6
Time (s)
Fig. 8.12
(a) Find how far does the car travel in the first 4 seconds.
Shade the area on the graph that represents the distance
travelled by the car during the period.
(b) Which part of the graph represents uniform motion of
the car?
ftnto which of the following situations are possible and give​

Answer 1

Answer:

Let us assume, the final velocity with which the ball will strike the ground be ‘v’ and the time it takes to strike the ground be ‘t’.

Given parameters

Initial Velocity of the ball (u) = 0

Distance or height of fall (s) = 20 m

Downward acceleration (a) = 10 m s-2

As we know

2as = v2 – u2

v2 = 2as +  u2

v2 = (2 x 10 x 20 ) + 0

v2 =  400

Final velocity of ball (v) = 20 ms-1

t = (v – u)/a

Time taken by the ball to strike (t) = (20 – 0)/10

t = 20/10

t = 2 seconds

The final velocity with which the ball will strike the ground is (v) =  20 ms-1

The time it takes to strike the ground (t) = 2 seconds

Explanation:

Answer 2

goven the car 810m aaaaaaaaaa