1.Distinguish between speed and velocity.
2.Convert a speed 54km/h into m/s
3.The odometer of a car reads 2000km at the start of a trip and 2400km at
the end of the trip. If the trip took 8 hours. Calculate the speed of the car
in ms'.
4.A car takes 10 hr to cover a displacement of 500km. What is the velocity
of car in ms''
Answers
Answer:
1. Speed is the time rate at which an object is moving along a path, while velocity is the rate and direction of an object’s movement.
2. Meters in 1 km = 1000
M in 54 km = 54000
Second in one hour = 60* 60= 3600
54km in m/sec = 54000/ 3600
= 15 m/sec
3. Initial odometer reading=2000km
Final odometer reading=2400km
Total distance= Final distance- Initial distance
=2400-200=400km
Total time=8h
Average speed =?
Formula to be used :
Average speed= Total Distance/Total time
Average speed in Km/hr:
Average speed=400/8
=50 km/hr
Average Speed in m/s:
1km/hr=5/18 m/s
∴50km/hr=50x5/18=250/18=13.88m/s
Explanation:
Took some time to calculate these, sorry.
Hope it helps.
Answer:
(1) .
Speed:
- It is defined as the rate of change of distance.
- It is a scalar quantity.
- It can never be negative or zero.
- Speed is velocity without direction.
- Speed may or may not be equal to velocity.
Velocity:
- It is defined as the rate of change of displacement.
- It is a vector quantity.
- It can be negative,zero or posituve.
- Velocity is directed speed.
- A body may possess different velocities but the same speed.
(2) .
Meters in 1 km = 1000
M in 54 km = 54000
Second in one hour = 60* 60= 3600
54km in m/sec = 54000/ 3600
= 15 m/sec
(3).
It is given that the total distance travelled by the car is 2400 km-2000 km = 400 km, that is, 400000 m and the total time taken =8 hours, that is, 8×60×60=28800seconds.
Average speed in m/s = total distance/total time = 400000/28800 = 13.89 m/s.
(4).
if distance = speed*time, then time = distance/speed
distance = 500 km
speed = 10 km/hr.
therefore,
time = (500km)/(10km/hr)
time = 50 hrs
velocity=50×5/18=13.88m/s