Answer:
(a)Average velocity ,v =128.74 Km/hr
(b)Kinetic Energy , K=958546.875 Joule
(c)Distance, s=268.8m
(d)Acceleration, a= - 2.38
<u>Explanation</u>:
<u>Given</u>:
Distance travelled = 40 miles
Time taken = 30 minutes.
(A) The average velocity in kilometres/hour
Converting 40 miles into km ,
we know that,
1 mile = 1.60934
40 miles = 40 x 1.60934
so 40 miles = 64.3738 Km
similarly converting 30 minutes into hours
1 minute =
30 minute =
30 minute =
Now
Average velocity =
Substituting Values,
Average velocity =
Average velocity =
Average velocity =128.74 Km/hr
(B) If the car weighs 1.5 tons, what is its If the car weighs 1.5 tons, what is its kinetic energy in joules (Note: you will need to convert your velocity to m/s)? in joules (Note: you will need to convert your velocity to m/s)?
Converting 1.5 tons into kg we get
1 ton = 1000 kg
so 1.5 ton =1500 kg
converting velocity to m/s
=>35.75 m/s----------------------------------------------------------(1)
kinetic energy K=
Substituting the values,
K=
K=
K=
K=
K=958546.875 Joule---------------------------------------------(2)
(c)When the driver applies the brake, it takes 15 seconds to stop. How far does the car travel (in meters) while stopping
Lets use Distance formula,
Substituting the known values,
-------------------------------------(3)
(D) What is the average acceleration of the car (in m/s2) during braking?
Using the formula
v=u +at
re arranging the formula we get,
Substituting the values
a= - 2.38 ----------------------------------------(4)
Now substituting 4 in 3 we get
s=268.8m--------------------------------------------------------------(5)