Question

A moving car is brought to rest within 2 second by applying breaks. If the reservation 3m per second square. What is the initial velocity?

Answer 1

Appropriate Question:

A moving car is brought to rest within 20 second by applying breaks. If the retardation is 3m per second square. What is the initial velocity?

Given Information:

• A moving car is brought to rest within 20 second by applying breaks.
• If the retardation is m/s^2
• What is the initial velocity?

Answer:

60m/s

Solution:

We have,

• Final velocity(v) = 0 m/s
• Time(t) = 20s
• Acceleration(a) = -3m/s^2
• Initial velocity (u) = ???

According to the 1st equation of motion, we have,

• v = u + at
• u = v - at
• u = 0 - ( -3) × 20
• u = 3m/s^2 × 20s
• u = 60m/s

Therefore, Initial velocity is 60m/s