Question

A truck starts from rest and rolls down a hill with constant acceleration. It travels a distance of 400m in 20s. Find its acceleration.find the force acting on it if its mass is 7 tonnes.
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Answer 1

A truck starts from rest and rolls down a hill with constant acceleration.

Starts from rest, means initial velocity(u)= 0 m/s

The truck travels a distance of 400m in 20s.

Distance (s) = 400 m and time (t) = 20 sec

We have to find the force acting on it if its mass is 7 tonnes.

Also given that, mass (m) = 7 tonnes = 7000 kg

Using Newton's Second equation of Motion

s= ut + 1/2 at²

→ 400 = 0(20) + 1/2 × a × (20)²

→ 400 = 0 + 1/2 × a × 400

→ 400 = 200a

→ a = 400/200

→ a = 2 m/s²

Now,

F = ma

→ F = 7000 × 2

→ F = 14000 kg m/s² or N

Answer 2

Answer:

• Acceleration of the truck = 2m/s².
• The force acting on it if it's mass is 7 tonnes is 14,000N.

Step by step explanation:

Given:

• Initial velocity (u) = 0
• Time taken by it (t) = 20sec
• Distance covered by it (s) = 400m

Need to find:

• Acceleration of the truck
• The force acting on it if it's mass is 7 tonnes.

Explanation:

As we know that,

S= it+1/2at²

Putting values in this formula,

we get:

=> 400 = 0×20+1/2×a×20²

=> 400 = 20+1/2a×400

=> 400 = a×200

=> 400/200 = a

=> 2ms² = a

Hence, acceleration of the truck is 2m/s².

Now,

Calculating force:-

f = m×a

=> 7×1000×2

=> 14,000 N

Hence, force acting on it if it's mass is 7 tonnes is 14,000N.