Question

A body is moving with a uniform acceleration covers 200m in the first 2s and 220 m in the next 4s. find the velocity in ms⁻¹ after 7s.

A. 10

B. 15

C. 20

D. 30

Answer 1

The velocity of the body after 7 seconds is 495 m/s.

Step-by-step explanation:

To find the velocity after 7 seconds, we need to determine the acceleration of the body. First, we calculate the acceleration during the first 2 seconds using the formula:

Acceleration = (final velocity - initial velocity) / time

Acceleration = (220 m/s - 0 m/s) / 4 s = 55 m/s²

Next, we can calculate the acceleration during the next 4 seconds:

Acceleration = (final velocity - initial velocity) / time = (v - 220 m/s) / 4 s = 55 m/s²

Since acceleration is constant, we can use the formula:

Final velocity = initial velocity + acceleration * time

For the first 2 seconds: final velocity = 0 m/s + 55 m/s² * 2 s = 110 m/s

For the next 4 seconds: final velocity = 220 m/s + 55 m/s² * 4 s = 440 m/s

To find the velocity after 7 seconds, we need to know the acceleration during the next 1 second. Since acceleration is constant, we can assume the same acceleration as the previous 4 seconds. Using the formula:

Final velocity = 440 m/s + 55 m/s² * 1 s = 495 m/s

Therefore, the velocity after 7 seconds is 495 m/s.