A bus decelerating with 4m/s2 changes its speed from 60 m s-1 to a certain value in 5 s. The final speed is:
Acceleration = – 4m/s2; Initial speed, u = 60 m s-1
Time taken = 5s
Acceleration = change in velocity per unit time
v= u + at
v = 60 – 4 x 5 = 40 m/s
If the upward direction is taken as positive what is the sign of velocity and acceleration when a body falls freely from a height.
A body moving along a straight line at 20m/s undergoes an acceleration of -4m/s2. After two seconds its speed will be
A boy throws a ball up and catches it when the ball falls back. In which part of the motion the ball is accelerating?
Choose the correct option:
Scalar quantities do not require direction, only magnitude is important. Distance does not require direction to speficy, therefore it is scalar, quantity.
Vector quantities require direction to specify.
Displacement is a vector quantity
Acceleration=final velocity-initial velocity/time
To calculate acceleration and velocity displacement is required, as displacement is vector quantity, therefore, velocity and acceleration are vector quantities.
The ratio of C.G.S. to M.K.S. unit of acceleration is:
M.K.S. unit of acceleration = 1m/s2
C.G.S unit of acceleration/ M,K.S unit of acceleration =
1cm/s2 / 1m/s2
= 1cm / 100 cm
The S.I. unit of acceleration is:
If a moving body comes to rest, then its acceleration is-
If a moving body comes to rest, then its acceleration is negative, as it's velocity becomes zero.
If the velocity of a body changes uniformly from u to v in time t, the sum of average velocity and acceleration is:
Acceleration is defined as the rate of change of: