Question

1. Tyrone is riding his newly bought motorcycle at 30 m/s when he sees a cat on the road ahead. He applied immediately the brakes and comes to a stop in 3.0 s. What was the acceleration of his motorcycle?
Given:

Asked:

Solution:

Final Answer:

2. A jeepney speeds up from 50 km/h to 60 km/h to overtake a truck. If this requieres 20 s, what is the (a) acceleration and (b) distance traveled by the car?

Given:

Asked:

Solution:

Final Answer:

Pls help​

Answer 1

Answer:

1. a = -10 m/s²

2. a = 1.8 × 10³ km/h²; s = 0.31 km

Explanation:

1.

Given:

Initial speed (u): 30 m/s

Final speed (v): 0 m/s (rest)

Time elapsed (t): 3.0 s

Asked:

Acceleration (a)

Solution:

We will use the following expression.

a = (v-u)/t = (0 m/s - 30 m/s)/3.0 s = -10 m/s²

Final Answer:

a = -10 m/s²

2.

Given:

Initial speed (u): 50 km/h

Final speed (v): 60 km/h

Time elapsed (t): 20 s

Asked:

(a) Acceleration (a)

(b) Distance traveled (s)

Solution:

(a) First, we will convert the time to hours.

20 s × 1 h/3600 s = 0.0056 h

Then, we will use the following expression.

a = (v-u)/t = (60 km/h - 50 km/h)/0.0056 h = 1.8 × 10³ km/h²

(b) We will use the following expression.

s = u × t + 1/2 × a × t²

s = 50 km/h × 0.0056 h + 1/2 × 1.8 × 10³ km/h² × (0.0056 h)² = 0.31 km

Final Answer:

a = 1.8 × 10³ km/h²

s = 0.31 km