Advertisements
Advertisements
Question
A bus moving along a straight line at 20 m/s undergoes an acceleration of 4 m/s2. After 2 seconds, its speed will be:
Options
8 m/s
12 m/s
16 m/s
28 m/s
Solution
28 m/s
Acceleration of the moving object is 4 m/s2
Initial velocity is 20 m/s.
Time taken is 2 sec.
By applying 1st equation of motion we get,
v = u + at
= 20 + 2(4)
= 28 m/s
So, the answer is
(d) 28 m/s
APPEARS IN
RELATED QUESTIONS
Abdul, while driving to school, computes the average speed for his trip to be 20 km h−1. On his return trip along the same route, there is less traffic and the average speed is 30 km h−1. What is the average speed for Abdul’s trip?
What is the SI unit of retardation ?
An aircraft travelling at 600 km/h accelerates steadily at 10 km/h per second. Taking the speed of sound as 1100 km/h at the aircraft’s altitude, how long will it take to reach the ‘sound barrier’ ?
A ball hits a wall horizontally at 6.0 m s-1. It rebounds horizontally at 4.4 m s-1. The ball is in contact with the wall for 0.040 s. What is the acceleration of the ball ?
The diagram below shows the pattern of the oil on the road at a constant rate from a moving car. What information do you get from it about the motion of the car.
The speed of a car is 72 km h-1. Express it in m s-1.
Arrange the following speeds in increasing order.
10 m s-1, 1 km min-1 and 18 km h-1.
A car is moving in a straight line with speed 18 km h-1. It is stopped in 5 s by applying the brakes. Find:
- the speed of car in m s-1
- the retardation and
- the speed of car after 2 s of applying the brakes.
A speeding car changes its velocity from 108 kmh−1 to 36 kmh−1 in 4 s. Calculate its deceleration in
- ms−2
- kmh−2.
A motorcyclist drives from A to B with a uniform speed of 30 km h–1 and returns back with a speed of 20 km h–1. Find its average speed.
