Advertisements
Advertisements
प्रश्न
When a car driver travelling at a speed of 10 m/s applies brakes and brings the car to rest in 20 s, then retardation will be :
विकल्प
+ 2 m/s2
− 2 m/s2
− 0.5 m/s2
+ 0.5 m/s2
Advertisements
उत्तर
+ 0.5 m/s2
The term “retardation” means negative acceleration.
Initial velocity = 10 m/s
Final velocity = 0 m/s
Time taken = 20 s
Acceleration = `"0-10"/20`
⇒ Acceleration = `-0.5 "m/s"^2`
⇒ Retardation = 0.5 `"m/s"^2`
APPEARS IN
संबंधित प्रश्न
Which of the two can be zero under certain conditions : average speed of a moving body or average velocity of a moving body ?
Fill in the following blank with suitable word :
Velocity is the rate of change of……………………… It is measured in.............. .
A bus running at a speed of 18 km/h is stopped in 2.5 seconds by applying brakes. Calculate the retardation produced.
A bus was moving with a speed of 54 km/h. On applying brakes it stopped in 8 seconds. Calculate the acceleration.
Derive the formula : v = u + at, where the symbols have usual meanings.
A train starting from stationary position and moving with uniform acceleration attains a speed of 36 km per hour in 10 minutes. Find its acceleration.
A car starting from rest acquires a velocity 180m s-1 in 0.05 h. Find the acceleration.
Write three equations of uniformly accelerated motion relating the initial velocity (u), final velocity (v), time (t), acceleration (a) and displacement (S).
Can you suggest a real-life example about the motion of a body from the following velocity – time graph?
A girl walks along a straight path to drop a letter in the letterbox and comes back to her initial position. Her displacement–time graph is shown in Fig.8.4. Plot a velocity-time graph for the same.
