1.What is the acceleration of a body moving with uniform velocity?
2. What does the slope of a distance-time graph gives?
3. Can displacement be zero even when distance is not zero? Give Example.
4. How can you get speed of an object from its distance – time graph?
5. How can you get distance of an object from its speed – time graph?
6. Can a body have zero velocity and still acceleration? Give example.
7. Is it possible in straight line motion a particle having zero speed and a non-zero
velocity? Explain.
8. On a 60 km straight road, a bus travels the first 30 km with a uniform speed of 30
kmh-1. How fast must the bus travel the next 30 km so as to have average speed of 40
kmh-1 for the entire trip?
9. A driver takes 0.20 seconds to apply the brakes. If he is driving car at a speed of 54
kmh-1 and the brakes cause a deceleration of 6.0 ms-2. Find the distance travelled by
the car after he sees the need to put the brakes.
10. A ball thrown vertically upwards with a speed of 19.6 ms-1 from the top of a tower
returns to the
earth in 6 seconds. Find the height of the tower. (g = 9.8 ms-2)11. A bullet initially moving with a velocity of 20m/s strikes a target and comes to rest
after penetrating a distance of 0.01m in the target. Calculate the retardation produced
by the target.
12. A body moving in a straight line at 72kmph undergoes an acceleration of 4m/s2.
Find its speed
after 2 seconds.
13. A car a moving at rate of 72km/h and applies brakes which provide a retardation of
5ms-2
a. How much time does the car takes to stop.
b. How much distance does the car cover before coming to rest?
c. What would be the stopping distance needed if speed of the car is doubled?
14. A body starts from rest and moves with a uniform acceleration of 5m/s2 for 5s and
then it moves with a constant velocity for 4s. Later it slows down and comes to rest in
5s.
15. Draw the velocity time graph for the motion of the body and answer the following
questions:
a) What is the maximum velocity attained by the body?
b) What is the distance travelled during this period of acceleration?
c) What is distance travelled when the body was moving with constant velocity?
d) What is the retardation of the body while slowing down?
e) What is the distance travelled by retarding?
f) What is the total distance travelled?
plz answer fast urgent
Answers
Explanation:
1. If a body is moving with uniform velocity in a given direction its acceleration will be zero.
2. In a distance-time graph, the slope or gradient of the line is equal to the speed of the object. The steeper the line (and the greater the gradient) the faster the object is moving.
3.Yes, the displacement can be zero even if the distance is not zero. Example – Circular motion of a body results in zero displacements but the distance cannot be zero.
4.If an object moves along a straight line, the distance travelled can be represented by a distance-time graph. In a distance-time graph, the gradient of the line is equal to the speed of the object. The greater the gradient (and the steeper the line) the faster the object is moving.
5.You can use the equivalent formula d = rt which means distance equals rate times time. distance = rate x time. To solve for speed or rate use the formula for speed, s = d/t which means speed equals distance divided by time.
6. Yes. When a body is thrown vertically upwards it has zero velocity at its highest point . Even then it has acceleration equal to the acceleration due to gravity in vertical motion.
7.No, it is not possible to have zero speed with non zero velocity in a straight line. If the speed of a body in a straight line is zero means the body is not moving So the rate of change of displacement is zero, that is the velocity of the body is zero.
8. Therefore bus should travel next 30km distance at a speed of 60 km/h.
9.Answer. Distance travelled in this time is S1 = 15 × 0.2 = 3 m.
12.The speed after 2 seconds is 0.02 km/s · 1 hour = 60 minutes = 3600 seconds · 1 seconds = 72/3600 kilometres = 0.02 kilometres.
Only this much answers I was having.
Sorry for not giving u full answers.
But I am still hopeful that my answers would be helpful.