To solve this problem, we can use the equation of motion:

d = ut + 0.5at^2

where:
- d is the distance travelled,
- u is the initial speed,
- t is the time, and
- a is the acceleration.

First, we need to convert the initial speed from km/hr to m/s because the time is given in seconds.

70 km/hr = 70 * 1000 m/3600 s ≈ 19.44 m/s

The final speed is 0, so the acceleration (which is actually deceleration in this case) can be found using the equation:

a = (v - u) / t

where:
- v is the final speed,
- u is the initial speed, and
- t is the time.

a = (0 - 19.44) / 3.6 ≈ -5.4 m/s^2

Now we can find the distance:

d = ut + 0.5at^2
d = 19.44 * 3.6 + 0.5 * -5.4 * (3.6)^2
d = 70 + -35.28 ≈ 34.72 m

So, the closest answer is a. 35 m.

Question

To solve this problem, we can use the equation of motion:

d = ut + 0.5at^2

where:
- d is the distance travelled,
- u is the initial speed,
- t is the time, and
- a is the acceleration.

First, we need to convert the initial speed from km/hr to m/s because the time is given in seconds.

70 km/hr = 70 * 1000 m/3600 s ≈ 19.44 m/s

The final speed is 0, so the acceleration (which is actually deceleration in this case) can be found using the equation:

a = (v - u) / t

where:
- v is the final speed,
- u is the initial speed, and
- t is the time.

a = (0 - 19.44) / 3.6 ≈ -5.4 m/s^2

Now we can find the distance:

d = ut + 0.5at^2
d = 19.44 * 3.6 + 0.5 * -5.4 * (3.6)^2
d = 70 + -35.28 ≈ 34.72 m

So, the closest answer is a. 35 m.

Knowee AI · Accepted Answer