Question

If you can answer both, please do. But if you can't, just answer one.

1. What average net force is required to stop a 7 kg shopping cart in 2 s if it’s initially traveling at 3.5 m/s?

2. What average net force is required to stop an 8500 kg truck in 10 s if it’s initially traveling at 20 m/s?

Answer 1

To stop the 7 kg shopping cart in 2 seconds from an initial velocity of 3.5 m/s, an average net force of -12.25 N is required. To stop the 8500 kg truck in 10 seconds from an initial velocity of 20 m/s, an average net force of -17000 N is required.

Step-by-step explanation:

1. To find the average net force required to stop the shopping cart, we can use the equation:

F = m * a

Where F is the force, m is the mass, and a is the acceleration. In this case, the acceleration is calculated using the formula:

a = (final velocity - initial velocity) / time

Substituting the given values, we have:

a = (0 - 3.5) m/s / 2 s = -1.75 m/s²

Now, we can calculate the force:

F = 7 kg * (-1.75 m/s²) = -12.25 N

Since force is a vector quantity, the negative sign indicates that the force is in the opposite direction of the initial motion.

2. Using the same equation, we can find the average net force required to stop the truck:

F = m * a

First, calculate the acceleration:

a = (0 - 20) m/s / 10 s = -2 m/s²

Substituting the given values:

F = 8500 kg * (-2 m/s²) = -17000 N

Once again, the negative sign indicates that the force is in the opposite direction of the initial motion.

Answer 2

1.The force required to stop the shopping cart is, F = 12.25 N

Explanation:

Given data,

The mass of the shopping cart, m = 7 kg

The initial velocity of the shopping cart, u = 3.5 m/s

The final velocity of the shopping cart, v = 0 m/s

The time period of acceleration, t = 2 s

The change in momentum of the cart,

p = m(u - v)

= 7 (3.5 - 0)

= 24.5 kg m/s

The force is defined as the rate of change of momentum. To stop the shopping cart, the force required is given by the formula

F = p / t

= 24.5 / 2

= 12.25 N

Hence, the force required to stop the shopping cart is, F = 12.25 N

2.

We have: F = m × v/t

Here, m = 8500 Kg

v = 20 m/s

t = 10 s

Substitute their values into the expression,

F = 8500 × 20/10

F = 8500 × 2

F = 17000 N

In short, final answer would be 17000 N

Hope this helps!!