Question

q4 if a car physics ch motion

Answer 1

You can use the eqautions of kinetics when solving questions that include uniform acceleration.

Answer 2

Hello Friend,

Here,
Initially car was at rest. So,
• Initial velocity = u = 0 m/s
• Final velocity = v = 144 km/h = 40 m/s

[1 km/h = 1000m / 3600s = 5/18 m/s]
[So, v = 144 × 5/18 m/s = 40 m/s]

• Let acceleration = a m/s²
• Time elapsed = t = 20 sec
• Let distance travelled = s metres

→ Now, we will first find acceleration:

v = u + at
So, 40 = 0 + a(20)
So, a = 40/20
So, a = 2 m/s²

→ Now, we can find distance travelled:

s = ut + ½ at²
So, s = (0)(20) + ½ (2)(20)²
So, s = 0 + 400
So, s = 400 m

→ Thus, distance travelled in 20 seconds is 400 metres. [Option B]


Hope it helps.

Purva
@Purvaparmar1405
Brainly.in