Questions about Chapter 2: Motion along a straight line.

Question
1: ** **

**The
motion of a particle ****traveling****
along the x-axis is described by the equation
**

**
x = 20 + 4 *
t ^{2}**

**where
x is in m and t in s.
**

**(a)
Find the average velocity of the particle in the time interval from t = 2
s to t = 5 s
(b) Find the instantaneous
velocity of the particle at t = 2 s.
**

**ANS:
(a)
28 m/s (b)
16 m/s**

Question
2: **
****
**

**A
ball is thrown vertically upward and reaches a maximum height of 35 m.
Upon descending to the ground it rebounds with half its initial velocity.
Find the height to which it climbs after rebounding ?
**

**ANS:
8.75 m.
**

Question
3: **
**

**A
stone is thrown vertically upward with a velocity of 9.8 m/s from the top of a
building whose height is 73.5 m. How
long will the stone take to reach the ground ?
**

**ANS:
5 s.
**

Question
4: **
****
**

**A
stone is dropped from the top of a very tall building.
One second later another stone
is thrown vertically downward with a speed of 12 m/s.
How far below the top of the building will the second stone overtake the
first ?
**

**ANS:
51 m.
**

Question
5: **
**

**A
car is initially travelling in a straight line and at a speed of 100 km/hr.
The driver accelerates the
car at a rate of 15 m/s ^{2} for 7 s.
How far does the car travel while it is being accelerated ?**

**ANS:
562 m.
**

Question
6: **
**

**A
ball is thrown vertically upward with an initial speed of 8.00 m/s from a height
of 30.0 m above the ground.
**

**(a)
When does the ball strike the ground ?
**

** (b)
Calculate the velocity of the ball just before it strikes the ground.**

Question
7:**
**

**A
stone is dropped from a bridge that is 940 m above the water.
Another stone is thrown vertically downward form this bridge 1.0 s after the
first stone is dropped.
Both stones strike the water at the same time.
**

**(a)
How long will it take the first stone to strike the water ?
**

**(b)
What was the initial speed of the second stone?
**