Question

A- A truck has a mass of 900 kilograms.

If the velocity of the truck is 20 m/s, what is its momentum?

1- 180000 kg·m/s

2-0 kg·m/s

3-9000 kg·m/s

4-18000 kg·m/s

B- If the truck is brought to a complete stop, what is the magnitude of the impulse that must be imparted to it?

1-18000 N·s

2-0 N·s

3- 9000 N·s

4-180000 N·s

C-If it takes 8 seconds to bring the truck to a stop, what is the magnitude of the force required to stop it?

1-1 × 105 N

2-0 N

3-0.0004 N

4-2250 N

Answer 1

A) momentum, \(P=m v\) \(\Rightarrow P=(900 \mathrm{~kg})(20 \mathrm{~m} / \mathrm{s})=18000 \mathrm{~kg} . \mathrm{m} / \mathrm{s}\)

Ans: 4

the magnitude of the impulse,

\(\Rightarrow I=\Delta P=m v-0\)

\(\Rightarrow I=(900 \mathrm{~kg})(20 \mathrm{~m} / \mathrm{s})=18000 \mathrm{~kg} \mathrm{~m} / \mathrm{s}\)

Ans: 1

the magnitude of the force, \(\Rightarrow\) impulse \(=\) Force \(^{*}\) time \(\Rightarrow F=\frac{(18000 \mathrm{~kg} . m / s)}{8 s}=2250 \mathrm{~N}\)

Ans:4