Question

A motorcyclist accelerates from
rest at a constant rate of 5m/s2 for
6seconds. He continues at a
constant velocity for the next
14 seconds before coming to rest in
10 seconds. Draw the velocity-time
graph for the above information and
calculate the total distance covered
during the entire journey.
8:03 PM

Answer 1

Answer: 220 m is Answer.

Explanation:

a = 5 m/s²

u =0

v =?

Distance covered by car when it was still accelerating in for 6 s is given by 2nd equation of motion,

S = ut + 1/2 at²

S1 = ut1 + 1/2at²1

= 0 + 1/2 × 5 × (6)²

= 90 m.

• Now, it attains a constant velocity for the next 14s. This constant velocity can be calculated using 1st equation of motion,

v = u + at

v = 0 + (5) x (14)

v = 70 m/s.

Now, let's calculate the distance travelled in next 14s before coming to rest in 10s. As the velocity attains the constant velocity, the acceleration will become zero.

Hence, S2 = ut2 + 1/2at²2

= 70 + (10) + 1/2(0)(10)²

S2 = 70 + 10 + 50 = 130 m.

Thus, the total distance covered in these 20 s = S1 + S2

= 90 + 130 = 220 m.