please answer 7,8,9 and 10.
Asked by Prashant DIGHE | 22nd Apr, 2020, 10:28: PM
Displacemet of particle,
x = 6 + 12t - 2t2 ......(1)
Q.6. time when velocity of particle is zero.
v = dx/dt
v = d (6 + 12 t - 2t2 )/dt
v = 12 - 4t ..... (2)
0 = 12 - 4(t)
Thus, t = 12/4 = 3 s
Hence, when velocity becomes zero time is 3 s.
Q.7. Displacement of particle after 2 seconds.
Displacement after 2 s = s(t=2) - s (t = 0) = [6 + 12 (2) - 2 (2)2 ] -  = 16 m
Q.8. Distance travelled after 2 seconds will be same as particle is moving in a straight line.
Thus, distance travelled = 16 m
Displacement of particle after 5 seconds.
Displacement after 5 s = s(t=5) - s (t = 0) = [6 + 12 (5) - 2 (5)2 ] -  = 16 - 6 = 10 m
Thus, displacement after 5 sceonds is 10 m
Q.10. Distance covered in first 5 s is,
In Q.6 we have seen that velocity becomes zero when t = 3s
It means particle travels forward direction for first 3 s and in backward direction for the next 2 s
Magnitude of displacement in first 3 seconds is
s(t=3) - s (t = 0) = [6 + 12 (3) - 2 (3)2 ] -  = 24 -6 =18 m
then displacement during 3s to 5 s time interval is,
s(t=5) - s (t = 3) = [6 + 12 (5) - 2 (5)2 ] - [6 + 12 (3) - 2 (3)2 ] = 16 - 24 = -8 m
Total distance covered by the particle in first 5 seconds is = 18 + |-8| = 18 + 8 = 26 m
Answered by Shiwani Sawant | 23rd Apr, 2020, 02:24: PM
- the display ment of a body is given to be proportional to the cube of time elapsed . the magnitude of the acceleration of the body is
- A car travels a distance 200m on a straight road in 2 minutes and then returns to the starting point in 4 minutes it's average speed is
- •A jogger runs in a straight line with –an average velocity of 5 m/s for 4 min. –an average velocity of 4 m/s for 3 min. •What is the total displacement? •What is the average velocity during this time?
- what is numerical ratio between velocity and speed
- If a man walk at a speed of 10 km/h, then find the distance traveled by the man in 5 hours?
- the velocity of a particle moving along x axis is given by v=x2 - x, where x is metre and v in m/s what is its position when velocity is minimum
- The distance between mumbai to delhi is 1384. A train starts from Mumbai at 4pm and reaches delhi at 10 am the next day.What is its average speed?
- the motion by body is described by the equation v=at square find the distance travelled by the body in the first 2second
- a man travels on a straight road from his home to the bank with a uniform speed of 18km/h for 10s and then travels with a uniform speed of 36 km/h for next 20 s on a straight road from bank to market. the average speed of the man for the whole journey is
- Derive an expression for average velocity and instantaneous velocity for the motion of an object in x-y plane.
Kindly Sign up for a personalised experience
- Ask Study Doubts
- Sample Papers
- Past Year Papers
- Textbook Solutions
Verify mobile number
Enter the OTP sent to your number