Advertisements
Advertisements
Question
A car traveling at 60 km/h, stops on applying brakes in 10 seconds. What is its acceleration?
Advertisements
Solution
First convert 60 km/h in m/s.
60 km/hr =(60 X 1000)/3600 = 16.7 m/s.
This is initial velocity of car i.e u = 16.7 m/s.
As car stops in 10 seconds so final velocity is =0 m/s.
So acceleration = (v-u)/t = (0-16.7)/10 = -1.67 ms-2.
Acceleration of car is = -1.67 ms-2.
APPEARS IN
RELATED QUESTIONS
An object of mass 16 kg is moving with an acceleration of 3 m/s2. Calculate the applied force. If the same force is applied to an object of mass 24 kg, how much will be the acceleration?
A space craft flying in a straight course with velocity of 75 km s-1 fires its rocket motors for 6.0 s. At the end of this time its speed is 120 km s-1 in the same direction.
Find
(i) The space craft's average acceleration while the motors were firing
(ii) The distance travelled by the space craft in the first 10 s after the rocket motors were started, the motors being in action for only 6 s.
A ball is rolling from A to D on a flat and smooth surface. Its speed is 2 cm/s. On reaching B, it was pushed continuously up to C. On reaching D from C, its speed had become 4 cm/s. It took 2 seconds for it to go from B to C. What is the acceleration of the ball as it goes from B to C?
A cyclist driving at 36 kmh−1 stops his motion in 2 s, by the application of brakes. Calculate
- retardation
- distance covered during the application of brakes.
What does a positive acceleration mean?
State if the following situation is possible:
A body moving horizontally with an acceleration in vertical direction.
A car is moving with a speed of 50 km/h. One second later, its speed is 55 km/h. What is its acceleration?
A bus can accelerate with an acceleration of 1 m/s2 . Find the minimum time for the bus to attain the speed of 100 km/s from 50 km /s.
Acceleration is defined as the rate of change of ______.
Assertion: A negative acceleration of a body can be associated with speeding up of the body.
Reason: Increase in the speed of a moving body is independent of its direction of motion.
